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Spectral selective coatings - equipment
|This page was developed by the Queen's University Applied Sustainability Research Group.|
- 1 Microscopy
- 2 Infrared Camera
- 3 UV SpectroscopyW
- 4 Glow Discharge Optical Emission Spectroscopy
- 5 Contact Angle GoniometerW
- 6 Veeco White Light Interferometry
- 7 Fourier Transform Infrared Spectroscopy
- 8 Single Wavelength Null Ellipsometer
- 9 Thermal Gravimetric Analyzer
- 10 Differential Scanning CalorimetryW
- 11 References
Microscopes are used to examine the surface of a sample at a higher magnification and resolution than can be obtained with the human eye. There are three main types; optical microscopesW (also referred to as light), electron microscopesW, and scanning microscopesW, all of which may be used for analyzing spectral selective coatings.
- Microscopy Techniques for Materials Science. Clarke, A.R., Eberhardt, C.N. 2002 (electronic resource) Available through Knovel.
- This online book covers the interaction of electromagnetic radiation with materials, microscope design, photonics, image processing, 2D optical and 3D Confocal laser scanning microscopy (of particular use may be the case study of a thin film particulate analysis). Electron microscopy (SEM/TEM) nuclear magnetic resonance (NMR) and ultrasonic imaging techniques are covered.
The optical microscope is the most common of all microscopes . They operate by focusing beams of light (could be visible, infrared or ultraviolet) through lenses to obtain typical resolutions of 0.2μm.  The level of resolution that a microscope has determines the level of detail that can be seen in the image. Resolution is the smallest distance in an image that can be distinguished as independent entities . Nikon has put together a page of resources known as MicroscopyU, providing an outline of the basic concepts and formulas used in light microscopy. It is available here: . Following is a list of some of the things this page covers:
- Field of View
- Depth of Field and Depth of Focus
- Image Brightness
- Microscope Ergonomics
- Refractive Index
- Multi-beam Interferometry
Authors of the various papers are provided at the bottom of each page, and are mostly from the National High Magnetic Field Laboratory associated with The Florida State University.
Optical microscopy has been used in various experiments, coupled with other techniques such as thermal analysis and x-ray diffraction to determine film properties
- Lifetimes of organic photovoltaics: Combining chemical and physical characterisation techniques to study degradation mechanisms. K. Norrman, N.B. Larsen and F.C. Krebs. Solar Energy Materials and Solar Cells. Volumne 90, Issue 17, 6, November 2006, Pages 2793-2814. 
Polarized Light Microscopy
This technique uses anisotropy (different properties in different crystallographic directions)to provide information that would otherwise be unavailable with normal light microscopy. Things like composition, and structure become more obvious. Although generally used in geology, polarized light microscopy can provide valuable information about composites, ceramics, and even biological materials like wood and DNA. Again, Nikon provides a good overview of how polarized light microscopy works complete with images .
In 2006, Daniel Kile a scientist with the US Geological Survey wrote an article Methods in Polarized Light Microscopy: An Overview and Historical Perspective, published in Microscopy and Microanalysis. In this paper he presents some of the techniques that can be used with polarized light microscopy and suggests that this technique should be taught more in universities because of the useful information that can be extracted . Those with access to the Proquest database should be able to access the article here: 
Scanning Electron Microscope
The first scanning electron microscope (SEM) was built in 1935 by Max Knoll , but it wasn't commercialized until 1965 when the Cambridge Instrument Company of England first began to sell them . The principal of the scanning electron microscope is similar to that of an optical or light microscope. An energy source, in this case electrons (as opposed to photons - light)are focused and moved accross the surface of the specimen using electromagnets. When the electrons hit the surface, they are reflected and captured by a screen
SEMs have a large depth of field and as a result their images have a 3-D quality, they are used to inspect semiconductors for defects. The following website provides a nice breakdown of the components of a SEM 
These microscopes operate in a vaccuum, because electrons do not travel well through air. Specimen considerations 
- Sample must be free of dust and debris
- If the sample is not conductive, it must be covered with a conductive coating like gold or platinum to ground the sample
- Samples can be coated using sputter coating
- If the sample is conductive (or once it is coated) it is affixed to a stage and mounted in the microscope's inner chamber
- Special care must be taken with biological samples (water will be drawn out in the vaccuum and will destroy the specimen). This should not be an issue when examining spectral selective coatings
Many studies have used SEMs to characterize photovoltaic materials. Some examples are linked below and will be accessible if you have a subscription
- Improving the photovoltaic response of a poly(3-octylthiophene)/n-Si heterojunction by incorporating double walled carbon nanotubespoly(3-octylthiophene)/n-Si heterojunctionby incorporating double-walled carbonnanotubes  (Improving the photovoltaic response of a poly(3-octylthiophene)/n-Si heterojunction by incorporating double-walled carbon nanotubes. Prakash R Somani, Savita P Somani, E Flahaut and M Umeno 2007 Nanotechnology 18 185708 (5pp) doi: 10.1088/0957-4484/18/18/185708)
- Construction of a photovoltaic device by deposition of thin films of the conducting polymer polythiocyanogen (Construction of a photovoltaic device by deposition of thin films of the conducting polymer polythiocyanogen. V. P. S. Perera, P. V. V. Jayaweera, P. K. D. D. P. Pitigala, P. K. M. Bandaranayake, G. Hastings, A. G. U. Perera and K. Tennakone.Synthetic Metals. Volume 143, Issue 3. June 21, 2004. Pages 283-287)
- Carbon nanotubes grown onIn2O3:Sn glass as large area electrodes for organic photovoltaics (Carbon nanotubes grown on In2O3:Sn glass as large area electrodes for organic photovoltaics. J. ; HATTON Ross A. ; CHEN G. Y. ; RAVI S. ; SILVA P.Applied physics letters 2007, vol. 90, no2)
Transmission Electron Microscope
The Nobel Prize in Physics 1986 was awarded to three researchers - Ernst Ruska, "for his fundamental work in electron optics, and for the design of the first electron microscope", and Gerd Binnig & Heinrich Rohrer, "for their design of the scanning tunneling microscope". Once again, the transmission electron microscope (TEM) operates in a similar way to an optical microscope. An electron beam is guided through a vaccuum tube by electromagnets that focus it into a very fine beam. The electrons travel to the specimen, some are scattered based on the density of the sample and so an image is created below the sample based on the remaining electrons. Nobelprize.org provides an overview of how to prepare a sample 
Atomic Force Microscopy
The atomic microscope was developped in 1985 by Binnig, Quate, and Gerber  and is not limited to imaging conductive or semiconductive materials like the aforementioned electron microscopes.
-  Does the local built-in potential on grain boundaries of Cu (In, Ga)Se2 thin films benefit photovoltaic performance of the device? F. S Jiang, R. Noufi, K. Ramanathan, J.A. AbuShama, h. R. Mountinho, M. M. Al-Jassim. Applied Physics Letters. Volume 85, Number 13.
- Atomic force microscope was used to verify charge storage in the thin film samples being tested. The ARM fast-scan direction was changed from lateral to vertical. AFM images were also used to measure change in grain size
- Contact mechanics and tip shape in AFM-based nanomechanical measurements. M. Kopycinska-Muller, R. Geiss and D. Hurley. Ultramicroscopy. Volume 106. Issue 6. April 2006. Pages 466-474
- Change in atomic force microscopy tip shape can lead to changes in what measurements are made on the sample, and artifacts may appear as a result. In this study a power law approach is used to account for changes in tip geometry.
Available at Queen's University, Kingston ON Canada
- Scanning electrochemical microscopy. Edited by Allen J Bard, Michael V. Mirkin. (2001) Call Number: QH212.S28 S32 2001
- Although focused on biological systems, this book provides information on instrumentation, and tips on sample preparation
- Imaging of surfaces and interfaces. Edited by Jacek Lipkowski, Philip N. Ross. (1999) Call Number: QD571.I43 1999
- Covers such topics as Electron diffraction and electron microscopy of electrode surfaces. Also examines high resolution imaging of metal electrocrystallization & scanning probe microscopy of thin organic films
- Microstructural characterization of materials. D.G. Brandon. (1999) Call Number: TA417.23.B73 1999
- Covers structure-property relationships, optical microscopes, electron microscopes, x-ray diffraction techniques, powder diffraction, sample preparation, semiconductors, ceramics, and intermetallics, chemical analysis of surface composition, and methods and considerations for the quantitative analysis of microstructure
- Transmission electron microscopy: physics of image formation and microanalysis. Ludwig Reimer. (1997) Call Number: QH212 T7 R43 1997
- Covers wave and particle aspects of the optics of electrons. Explains how to image crystalline specimens and their defects, and looks at scattering and phase contrast for amorphous specimens
- Transmission electron microscopy: A textbook for materials Science. David B. Williams, C.Barry Carter. Call Number:
- Chapers cover the use of electrons for image viewing, along with the limitations of this procedure. Preview only available online
- A transmission electron microscope investigation of structural defects in M.B.E. grown ZnSe films. Sudhindra B. Sant. (1989) Call Number: Microfiche no.390
- PhD thesis available in Stauffer
-  Campbell, Jennifer. Design and Fabrication of a Nanocantilever for High-Speed Force Microscopy. 2-Feb-2009.
- Recognizing that the AFM is an important tool in materials science, probe scanning speed is manipulated in this PhD thesis to allow for dynamic imaging. The author focuses on creating a cantilever with a resonance frequency of greater than 100MHz by miniaturizing it to the nano scale.
-  Handbook of molecular force spectroscopy [electronic resource] / edited by Aleksandr Noy.
- This electronic resource covers some biological examples, but also looks at chemical force microscopy, and dynamic force spectroscopy with the atomic force microscope
- Surface and thin film analysis : principles, instrumentation, applications. Edited by H. Bubert and H. Jenett. 2002 Call Number: QC176.84.S93 S87 2002
- This book covers a number of analysis methods for use with thin films including, but not limited to: AFM, Ion Beam Spectral Analysis, Energy Ion Scattering, photoelectron spectroscopy and several other techniques.
-  Article: Photovoltaics:Shortwave infrared cameras characterize thin film solar cells.
- Article: Using of IR thermography for the performance assessment of building photovoltaic array. Takes advantage of not needing to interrupt operation of the system when using IR thermography to analyze the photovoltaic system at the National Technical University of Athens. Using this technique they were able to locate areas of internal weakness where no external signs were visible on the panels.
- [ http://www.youtube.com/watch?v=PMpgeFoYbBI]Although not completely scientific, this one is interesting and shows you how to make an infrared camera filter for your digital camera. This is not recommended for any scientific experiments!
All substances absorb different amounts of light based on their functional groups. It is possible to take advantage of these absorption differences to identify unknown substances by comparing the intensity of a light that has passed through an unknown sample to a reference beam of light. An excellent description of how spectroscopy works can be found here: .
One manufacturer of spectrophotometers is Varian. The spectrophotometer that we have access to is the Varian Cary 5000 UV-VIS-NIR spectrophotometer. Some of the material specs are listed below. All are available here:  from the supplier
Varian Cary 5000 UV-VIS-NIR spectrophotometer
- Wavelength: 175-3300 nm
- Optics are isolated from external disturbances
- PbSmart Technology to provide improved noise and linearity performance
- Lock down mechanism to allow for easy experimental set up
To increase the range over which the Varian can operate, an integrating sphere is added
Mid-IR IntegratIR – Integrating Sphere
Our equipment also includes a ‘’’Mid-IR IntegratIR – Integrating Sphere’’’ manufactured by PIKE Technologies. The integrating sphere extends the wavelengths that can be used to measure emissivity over a relevant range for solar thermal applications. This equipment is necessary in order to characterize the thin film selective absorber coatings over the full spectrum. Product Specifications can be found here . Some features include
- 8 degree hemispherical diffuse reflectance to collect full reflectivity from the sample
- In sample compartment design to minimize space requirements
- Spectral range to 550 cm-1
Glow Discharge Optical Emission Spectroscopy
Glow Discharge Optical Emission Spectroscopy (GDOES) is a depth profiling technique.GD-OES is an extremely powerful tool for the control and monitoring of industrial processes, the identification of defects and assistance in tracing the causes of quality problems. Glow Discharge Spectrometer is the ideal tool to investigate from the surface down to more than 150 microns with a depth resolution that can be as good as 1 nm. It is an ideal tool for thin film characterization and process studies.
The LECO GDS-850A optical emission spectrometer utilizes the principle of an electric discharge in a low-pressure argon atmosphere, with atoms continuously being sputtered (eroded) from the sample’s surface by the bombardment of argon ions (discharge plasma). 
Glow discharge spectroscopy (GDS) is also known as glow discharge lamp (GDL); glow discharge lamp spectroscopy (GDLS); glow discharge optical spectroscopy (GDOS); glow discharge optical emission spectroscopy (GDOES); or glow discharge atomic emission spectroscopy (GDAES). The techniques are essentially the same if they use the classic GRIMM lamp technology. If the spectrometer is equipped only with a radio frequency (RF) source (lamp), it may be referred to as RF-GDS.
The following are features of the GD-OES spectrometer:
- Analysis on any solid conductive materials that a plasma can be initiated and maintained on.
- Detection limits: ppm sensitivity, bulk mode.
- Minimal spectral and metallurgical interference.
- Complex multi-matrix algorithms correct for sputter rate variations in different materials, allowing for Quantitative Depth Profiling.
- Determine the thickness and composition of surface layers and coatings.
- The sputter produces an analysis area that is a 4-mm diameter flat bottom crater.
- Glow Discharge . Com, GDOES Quantification 
- Depth profiling by GDOES: application of hydrogen and d.c. bias voltage corrections to the analysis of thin oxide films. J. Michler, M. Aeberhard, D. Velten, S. Winter, R. Payling and J. Breme. Thin Solid Films Volumes 447-448, 30 January 2004, Pages 278-283 Proceedings of the 30th International Conference on Metallurgical Coatings and Thin Films 
- R. Payling, T. Nelis,Glow Discharge Optical Emission Spectroscopy, A Practical Guide,2003 (need to purchase)
- Papers using GDOES for Solar Applications:
Fernando, C.A.N.; de Silva, P.H.C.; Wethasinha, S.K.; Dharmadasa, I.M.; Delsol, T.; Simmonds, M.C., Investigation of n-type Cu2O layers prepared by a low cost chemical method for use in photovoltaic thin film solar cells ,Renewable Energy,vol.26,no.4,pp.521-529,Aug. 2002.
Abstract:A low cost and simple chemical method of boiling copper plates in CuSO4 Solution is used to prepare Cu2O layers. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), glow discharge optical emission spectroscopy (GDOES) and optical absorption have been used to characterise these layers. It has been found that the layers consist of Cu2O phase with a thickness of about 1.4 μm for 60 minutes boiling in CuSO4 solution. The largest grain sizes are in the order of 1 μm and the layer's contain cubic Cu2O phases. The layers are n-type in electrical conduction and the optical band gap observed is 2.2 eV
Delsol, T.; Samantilleke, A.P.; Chaure, N.B.; Gardiner, P.H.; Simmonds, M.; Dharmadasa, I.M.,Experimental study of graded bandgap Cu(InGa)(SeS)2 thin films grown on glass/molybdenum substrates by selenization and sulphidation,Solar Energy Materials and Solar Cells,vol.82,no.4,pp.587-599,30 May 2004
Abstract...Full characterizations have been carried out using X-ray diffraction, Raman, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy (XPS), X-ray fluorescence, inductively coupled plasma mass spectroscopy, glow discharge optical emission spectroscopy (GDOES) and photoelectrochemical (PEC) techniques to study various properties. The material layers were found to be polycrystalline with the (112) preferred orientation, and the largest grains were about 2 μm....
Library Resources Available at Queen's University, Kingston, ON, Canada.
- Edited by H. Bubert and H. Jenett, Surface and thin film analysis : principles, instrumentation, applications, Weinheim : Wiley-VCH, c2002,
Location: Engineering & Science Library - Books Call Number: QC176.84.S93 S87 2002
This book covers GDOES under Photon Detection.
- Edited by D. Brune [et al.], Surface characterization : a user’s sourcebook, Scandinavian Science Publisher ; Weinheim ; New York : Wiley-VCH, c1997.
Location: Engineering & Science Library - Books Call Number: TP156 .S95 S86 1997t
GDOES used for characterising Microstructure and topography.
Kadra09 14:58, 17 June 2009 (UTC)
Contact Angle GoniometerW
Contact angle goniometers are used to measure contact angles as they change with time, along with surface tension. In the field of crystallography, goniometers measure the angles between crystal faces.
-  YouTube video showing ramé-hart Goniometer of contact angle for super hydrophobic material
-  YouTube video showing ramé-hart Goniometer for dynamic contact angle with hydrophilic sample
- Simulation of Engineered Nanostructured Thin Films. Jason Cheung. 2009. Online. 
- Includes such topics as glancing angle deposition, nanostructured thin films, montecarlo analysis, surface growth model, surface diffusion, crystal microstructure, and vapour deposition.
-  Assembly and characterization of colloid-based antireflective coatings on multicrystalline silicon solar cells. Journal of materials chemistry. 2007. Vol. 17 Iss. 8 Pg 791
- Nanoscale antireflective coating was fixed to top of solar cell. Relative efficiency was improved by 10%. A contact angle goniometer was used to complete static contact angle experiments according to the procedures described in the literature. Contact angles of water droplets on the coated surfaces and uncoated surfaces were found to be identical.
- Enhancement of photovoltaic characteristics using a PEDOT interlayer in TiO2/MEHPPV heterojunction devices. Mi Yeon Song, Kang-Jin Kim, and Dong Young Kim. Solar Energy Materials and Solar Cells. Volume 85 Issue 11 Jan 2005. Pages 31-39
- Treating the surface of their cells with an oxygen plasma treatment, researchers were able to confirm that the surface had changed from hydrophobic to hydrophilic by measuring a contact angle goniometer and the static sessile drop method. Contact angle changed from 90º to 40º
- Improved performance of dense TiO2/CdSe coupled thin films by low temperature process. R.S. Mane, Seung Jae Roh, Oh-Shim Joo, C.D. Lokhande and Sung-Hwan Han. Electrochimica Acta. Volume 50, Issue 12. April 15,2005. Pg. 2453-2459
- Found TiO2 film to have a higher water contact angle than TiO2/CdSe and CdSe.
Veeco White Light Interferometry
Using white light interferometry, scientist and researchers are able to determine the topography of a fairly large area (up to 15mm)  A paper by James Wyant of the University of Arizona, looked at the advantages and disadvantages of white light interferometry compared ot laser light interferometry. Following are some of his comments. Interference fringes are easily obtained with white light, these are easier to find than ones produced by a laser, unfortunately stray reflections may lead to measurement error. There are three different types of white light interferometers: diffraction grating, vertical scanning/coherence probe and scatterplate .
The following paper describes how white light interferometry works (White Light Interferometry, a method for optical 3D-inspection of advanced packages. M. SCHAULIN, K. 3. WOLTER Elecrronics Packagiiig LaLoraroty,Drerden University of Tecluralogy)
Other research that has used white light interferometry as a materials surface characterization method:
-  Radiometric Characterization of a New Photovoltaic Cell Unit for Powering Modulating Retroreflectors. June 19, 2007. This paper presents two different options for radiometric characterization. It also has a section on the “whitelight radiometric characterization of the PV wafer using the Integrating-Sphere radiance source”
-  Lateral homogeneity of porous silicon for large area transfer solar cells. In this experiment, local porosity of their samples was determined using white-light interferometry. (Lateral homogeneity of porous silicon for large area transfer solar cells.O. Tobail, Z. Yan, M. Reuter and J.H. Werner.Thin Solid Films. VOlume 516, Issue 20, 30 August 2008, Pages 6959-6962.Proceedings on Advanced Materials and Concepts for Photovoltaics EMRS 2007 Conference, Strasbourg, France)
- Nitrided-organic hybrid heterostructures for possible novel optoelectronic devices: charge injection and transport. In this experiment RMS roughness of the InGaN surface was measured before and after deposition of an organic layer. (Nitride-organic hybrid heterostructures for possible novel optoelectronic devices: charge injection and transport. Hyunjin Kim, Qiang Zhang, Yoon-Kyu Song, Arto Nurmikko, Qian Sun, Jung Han. Physica Status Solidi.Volume 6, Issue 2. Pages 593-595)
References and further reading may be available for this article. To view references and further reading you must purchase this article.
Fourier Transform Infrared Spectroscopy
As with all types of absorption spectroscopy, a relationship exists between the intensity of the radiation that is transmitted, reflected, and the amount of sample in the beam, according to the Beer-Lambert Law:
I=I0exp(-εcl), where c is the concentration, l is the thickness of the material and ε is the frequency dependent extinction coefficient. Fourier Transform Infrared Spectroscopy (FTIR) combines the original design of the interferometer and math (fourier transform) to avoid the usual difficulties of long sample time needed or the poor signal to noise ratio. 
Studies that have used FTIR to characterize InGaN PV cells include:
- T. R. Baisitse, A. Forbes, G. Katumba, J. R. Botha, and J. A. A. Engelbrecht. “Characterisation of InAs-based epilayers by FTIR spectroscopy”. Papers presented at the E-MRS 2007 Spring Meeting-Symposium F Novel Gain Materials and Devices Based on III–N–V Compounds. Strasbourg, France. May 28- June 1 2007. p537-536 (paper unavailable)
Books available in the library that reference FTIR Spectroscopy that may be of some use
- Frontiers in analytical spectroscopy . Edited by: D.L. Andrews, A.M.C. Davies. Call Number: QD95 .F76 1995t
- Collection of articles dealing with leading edge technology (in 1995) and how it was being used. Of particular interest may be an article entitled: Electrochemically Modulated Infrared Spectroscopy Using a Step-scanning FTIR Spectrometer
- A matrix isolation spectroscopic investigation of the reaction products of transition metal centres with ethene and water. by Matthew G.K. Thompson. 
- This is a chemistry PhD thesis. Reaction products of ethane isotope are examined using Fourier Transfrom Infrared Spectroscopy
- Several examples of books using FTIR to characterize polymers and microbiology examples
Single Wavelength Null Ellipsometer
Single wavelength null ellipsometers can be used to determine layer thickness. In a paper by Easwarakhanthan, T . and Alnot, P, the data generated by a single wavelength null ellipsometer determined the interface layer thickness between the bulk SiO2 silm and Si substrate . This operation has been described as bieing simple and stable, and can be used to measure the deposition of mass due to macromolecular adsorption 
- Determination of the optical constants of zinc oxide thin films by spectroscopic ellipsometry. Washington, P.L. Ong, H.C., Dai, J.Y., Chang, R.P.H. Applied Physics Letters 
- Used Spectroscopic ellipsometers to determine the pseudo dielectric functions of Al2)3. Refractive indexes were also determined below the bandgap
- Dielectric functions and optical parameters of Si, Ge, GaP, GaAs, GaSb, InP, InAs, and InSb from 1.5 to 6.0 eV. Aspens, D.E. and Studna, A.A. Phys. Rev. B 27, 985-1009 (1983)
- Again, pseudodielectric functions are reported. Measured using spectroscopic ellipsometry, and are used to calculate reflectivities and absorption coefficients.
Books that may be helpful available at Queen’s University
- Surfaces, interfaces, and thin films for microelectronics. Irene, Eugene A. 2008. Call Number: QD506 .I74 2008
- Chapter 9 covers Ellipsometry and optical properties of surfaces, interfaces and films. This book also looks at thermodynamics of thin film surfaces, charged surfaces, surface roughness and adsorption.
- Handbook of Ellipsometry. Edited by Harland G. Tompkins and Eugene A Irene. 2005. Online 
- ”Provides an essential foundation for the current science and technology of ellipsometry for scientists and engineers in industry and academia”. Reviews instrumentation, critically reviews some applications (including SiO2 films, and new emerging areas.
- Infrared ellipsometry on semiconductor layer structures: phonons, plasmons, and polaritons. Mathias Schubert. 2004. Online  or in print Call Number: QC1. S797 v.209
- Covers ellipsometry, infrared model dielectric functions (which papers have used single wavelength null ellipsometry to predict), polaritons in semiconductor layer structures, and much more
- Surface and thin film analysis: principles, instrumentation, applications. Edited by H. Bubert and H. Jenett. 2002. Call Number: QC176.84.S93 S87 2002
- Covers different methods of spectroscopy including photoelectron, auger electron, low-energy, static secondary ion mass, and dynamic secondary ion mass spectroscopy. Several Xray detection methods are also described along with some microscopy descriptions.
Thermal Gravimetric Analyzer
Thermal gravimetric analysis (TGA) measures the weight change of a sample with temperature. This can provide information about drying, gas evolution, re-hydration, and structural decomposition.  Images of what TGA’s look like can be seen here: . Sample sizes range from 0.1-60 mg. Thermal gravimetric analysis also allows prediction of aging times through kinetic studies 
Potentially Useful Papers:
- In situ quaterizable oligo-organophosphazene electrolyte with modified nanocomposite SiO2 for all-solid-state dye-sensitized solar cell. Wanchun Xiang, Yanfang Zhou, Xiong Yin, Xiaowen Zhou, Shibi Fang, Yuan Lin. 
- Completed TGA analysis over a range of 20-700ºC
- High-performance polymer heterojunction solar cells of a polysilafluorene derivative. Ergang Wang, Li Wang, Linfeng Lan, Chan Luo, Wenliu Zhuang, Junbiao Peng, and Yong Cao. . Applied Physics letters
- Demonstrated thermal stability of polymer cells using TGA testing.
- There are also several papers dealing with organic solar cells using thermal gravimetric analysis to prove material stability. , , 
Differential scanning calorimeters measure the difference in heat flow between a reference material and a sample subjected to the same temperature difference. This can be used to determine both the temperature and heat of transformation.
- Sensys Evo Differential Scanning Calorimeter from Setaram demonstration and explanation from a trade show
- TA instruments demonstrates their new Q series differential scanning calorimetry. Note - Goal of video is sales.
- Thermodynamics and kinetics of phase transformations : Symposium held November 27-December 1, 1995. Boston Massachusetts. 1996. Call Number: QC175.16.P5 T485 1996t
- One paper presented performs under-cooling experiments in a high temperature differential scanning calorimeter
Papers that may be helpful
There are several studies that use differentials scanning calorimetry in the study of dye-sensitized and organic solar cells. Others use this process to examine crystallization kinetics. Some examples follow:
- Crystallization kinetics of a bulk amorphous Cu-Ti-Zr-Ni alloy investigated by differential scanning calorimetry. Y.J. Yang, D.W. Xing, J. Shen, J.F. Sun, S.D. Wei, H.J. He and D.G. McCartney
- Activation energies for the glass transition and crystallization at onset were determined using differential scanning calorimetry for bulk amorphous Cu52.5Ti30Zr11.5Ni6
-  Photovoltaic solar cell using poly(3,3-didodecylquaterthiophene. G. Wantz, F. Lefevre, M.T. Dang, D. Laliberté, P.L. Brunner and O.J. Dautel. 2007. Solar Energy Materials and Solar Cells. Volume 92, Issue 5, May 2008. Pages 558-563
- Used differential scanning calorimetry to study thermal characteristics (transitions) of 12 PQT. Information about scanning rate given. They compare their results to those given in another paper
- Nanoscale structure of solar cells based on pure conjugated polymer blends. Sjoerd C. Veenstra, Joachim Loos, Jan M. Kroon. Progress in Photovoltaics: Research and Applications. Volume 15. Issue 8. Pages 727-740. 2007.
- Provides an overview of photovoltaics based on blends of semiconducting polymers. Glass transition temperatures are determined using differential scanning calorimetry.
- Microscopy and Analysis. John Wiley and Sons. 2008. [online] http://www.microscopy-analysis.com/index.php?q=light. Accessed June 8, 2009.
- Davidson, Michael. “Resolution”. Nikon MicroscopyU. [online] http://www.microscopyu.com/articles/formulas/. Accessed June 8, 2009.
- Wang, M.,Yang, G.Z.,Wang, W.Z., Wang, M. “Morphological effect on spectral property of poly(9,9-dihexylfluorene-alt-2,5-dihexyloxybenzene) films” European Polymer Journal (2007): 4613-4618. 8 Jun. 2009 < http://scholarsportal.info/cgi-bin/sciserv.pl?collection=journals&journal=00143057&issue=v43i0011&article=4613_meospopf>
- D Kile. "Methods in Polarized Light Microscopy: An Overview and Historical Perspective. " Microscopy and Microanalysis 2.S02 (2006): 224-225. ProQuest Nursing & Allied Health Source. ProQuest. Queen's University Library.8 Jun. 2009 <http://www.proquest.com/>
- Woodford, C. "Electron Microscopes: ExplainThatStuff." June 24, 2007. [online] http://www.explainthatstuff.com/electronmicroscopes.html June 9,2009.
- Atteberry, Jonathan. "How Scanning Electron Microscopes Work" 2009. [online] http://science.howstuffworks.com/scanning-electron-microscope1.htm. June 10, 2009.
- Nobelprize.org "The Transmission Electron Microscope: Microscopes" [online] http://nobelprize.org/educational_games/physics/microscopes/tem/index.html. June 9, 2009.
- The A to Z of Materials (AZOM),Glow Discharge Optical Emission Spectroscopy ( GD-OES ) – A Depth Profiling Technique ,Source: Materials World, Vol. 9, No. 4 pp. 9-10, April 2001
- Horiba Scientific, http://www.horiba.com/us/en/scientific/products/atomic-emission-spectroscopy/glow-discharge//?Ovly=1
- Twin Analytical Ltd.,Glow Discharge Optical Emission Spectroscopy, http://www.twinanalytical.com/instruments/GD-OES.php
- Zecchino, M. Olszak, A. High Speed Surface Measurement with Lateral Scanning White Light Interferometry. Veeco Instruments Inc. Tucson Arizona. 2002. Online [htto://www.veeco.com/pdfs/appnotes/an502_59.pdf] Accessed June 12,2009.
- Wyant, J. “White Light Interferometry”. Optical Sciences Centre. University of Arizona, Tucson. Online. www.optics.arizona.edu/jcwyant/pdf/meeting_papers/whitelightinterferometry.pdf. Accessed June 12, 2009
- Sheffield Hallam University. Materials and Engineering Research Institute. Equipment and specialist techniques: FTIR spectroscopy – basic theory. Online. http://www.shu.ac.uk/research/meri/equipment/spectroscopy.html
- H. Tompkins, E. Irene. “Handbook of ellipsometry” Online 
- Orton. “Thermal Gravimetric Analysis”. Servicios e Instrumentos de México, S.A de C.V. [online] http://www.si-mex.com.mx/PDFS/orthon/Thermal%20Gravimetric%20Analysis%20brochure.pdf
- Carderock Division. “Thermal Gravimetric Analyzer.http://www.dt.navy.mil/sur-str-mat/fun-mat/fir-pro-sea/the-gra-ana/index.html
- Differential Scanning Calorimetry. Setaram Instrumentation. 2009. Online. http://www.setaram.com/Differential-Scanning-Calorimetry-DSC-Differential-Thermal-Analysis-DTA.htm. Accessed June 16, 2009,