The edit can be undone. Please check the comparison below to verify that this is what you want to do, and then publish the changes below to finish undoing the edit.
Latest revision | Your text | ||
Line 62: | Line 62: | ||
Additionally, there are two main strategies employed to reduce this lattice mismatch effect. The first involves using a '''buffer layer''' between two lattice-mismatched materials to match the lattice constants. This buffer layer is typically step-graded meaning its lattice constant is slowly altered by changing the composition so that either end of the buffer layer matches its adjacent subcell. The second method uses an '''inverted growth''' method to avoid lattice mismatch effects if the top layers are matched but the bottom layers are not. The growth process is reversed starting with the top layer (widest band gap) and adding subsequent layers. The substrate the top layer was grown on is then etched off after wards. Figure 6 shows the process for a triplet MJ cell for lattice matched top (InGaP) and middle (GaAs) layers with a lattice mismatched bottom cell (InGaAs). | Additionally, there are two main strategies employed to reduce this lattice mismatch effect. The first involves using a '''buffer layer''' between two lattice-mismatched materials to match the lattice constants. This buffer layer is typically step-graded meaning its lattice constant is slowly altered by changing the composition so that either end of the buffer layer matches its adjacent subcell. The second method uses an '''inverted growth''' method to avoid lattice mismatch effects if the top layers are matched but the bottom layers are not. The growth process is reversed starting with the top layer (widest band gap) and adding subsequent layers. The substrate the top layer was grown on is then etched off after wards. Figure 6 shows the process for a triplet MJ cell for lattice matched top (InGaP) and middle (GaAs) layers with a lattice mismatched bottom cell (InGaAs). | ||
[[File:Invertgrowth.JPG|thumb|center|Figure 6: Lattice mismatch inverted growth method | [[File:Invertgrowth.JPG|thumb|center|Figure 6: Lattice mismatch inverted growth method]] | ||
== Materials == | == Materials == |