Strain effect for different phosphorus content of InGaAs/GaAsP super-lattice in GaAs p-i-n single junction solar cell

The GaAs p-i-n single junction solar cell with InGaAs/GaAsP super lattice (SL) in the i-region was fabricated by metal organic vapor phase epitaxy (MOVPE). Using the in situ wafer curvature monitoring, a series of SL solar cell samples with different phosphorus composition in the barrier GaAsP layer was evaluated the accumulated strain during MOVPE growth. The sample with larger phosphorus content in GaAsP barrier layer reduced total strain accumulation, resulted in improved solar cell performance regardless to the higher potential barrier. This result indicated the about 3-nm thick barrier is sufficiently thin for carrier extraction by assisting the tunneling effect. Furthermore, the accumulated strain during MOVPE growth of SL deteriorate solar cell. (C) 2014 Elsevier B.V. All rights reserved.