The Quantum Efficiency (QE)/IPCE measurement system measures the spectral responsivity of photovoltaic cell. The system uses monochromatic light source to apply specific wavelength to the device under test. It uses transimpedence amplifier to convert the induced current in the test device to a voltage, which is measured with signal conditioning equipmentand digital signal processing software. A computer controls the system components, automating data collection, analysis, reporting and calibration. The installed system is referred as the QEX10- a PV Measurements, Inc. product
System Options
A wide range of optional features are included within this system: 1. Beam-up operation 2. Beam-down operation 3. Spectral range extension to 1800 nm 4. LED bias light 5. Vacuum test fixture, 160mm X 160mm 6. Thermoelectric temperature control for vacuum test fixtures
Spectral Response
Quantum efficiency is the ratio of number of electrons delivered to an external circuit to the number of photons striking the device surface- generally expressed as a function of incident light wavelength. A solar cell's quantum efficiency graph provides a quick visual indication of the wavelengths at which there are room for improvement. The information can also be used , in conjunction with reference device quantum efficiency and test source spectrum, to compute the spectral mismatch parameter that can be applied in setting solar simulator intensity for efficiency tests. Additionally by integrating the product of the spectral response with the spectral irradiance at each wavelength the short circuit current density (Jsc) of the test devices can be estimated.