Concentration enhancement of current density and diffusion length in III–V ternary compound solar cells

Current density and output power of solar cells, respectively, made from different materials combinations: GaAsp(:Zn)/GaAsP(:Te)/GaAs-CVD GaAsp(:Zn)/GaAs(:Te)/GaAs-CVD GaAlAs(:Zn)/GaAs(:Si)-LPE Silicon,p onn (commercial grade) have been compared at increasing light levels, i.e. solar concentrations from 1 sun to 100 suns. A strongly super-linear increase in output (current density) is found for the ternary compound cells in agreement with earlier measurements. The faster rate of increase of the current with concentration in ternary compounds as compared to silicon can be explained by a trap-filling mechanism at higher injection levels. A Gaussian distribution of compensated donor states can explain the superlinear current increase.