The effect of various window layers for InP solar cells are studied. Window materials that have type I and type II alignments in the window/emitter interface are compared. All window materials that form a type II alignment with InP, such as Al/sub 0.20/In/sub 0.80/P, Ga/sub 0.20/In/sub 0.80/P, Al/sub 0.55/In/sub 0.45/As and Al/sub 0.60/In/sub 0.40/P, cause a high interface recombination velocity, which deteriorates the carrier collection. This recombination takes place due to the spatially indirect quantum well transition between the triangular quantum wells formed in the interface. ZnSe as a window layer material with type I alignment does not have this problem, but decreased response in the short wavelength region is observed due to misfit dislocation induced trap sites. Future prospects for the window layer development for InP are discussed. The discussion is extended also to other III-V semiconductor based solar cell materials, such as Ga/sub 0.5/In/sub 0.5/P solar cells with Al/sub x/Ga/sub 1-x/As window layers.
|Title of host publication||Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)|
|Publisher||IEEE Institute of Electrical and Electronic Engineers|
|Publication status||Published - 1994|
|MoE publication type||A4 Article in a conference publication|
Lammasniemi, J., Tappura, K., & Smekalin, K. (1994). Recombination mechanisms at window/emitter interface in InP and other III-V semiconductor based solar cells. In Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC) IEEE Institute of Electrical and Electronic Engineers. https://doi.org/10.1109/WCPEC.1994.520562