GaSb-based (thermo)photovoltaic cells with Zn diffused emitters

GaSb-based (thermo)photovoltaic cells were formed by Zn-diffusion into n-doped wafers. Two-dimensional simulations of GaSb cells varying the emitter structure and illumination conditions (AM1.5D, AM1.5D under GaAs, spectra of IR light sources) were performed. A comparison of different Zn diffusion methods showed that the diffusion from the vapor phase in a pseudo-closed-box system is the most simple, reproducible and results in the highest efficiency of the cells. An efficiency of 7.3% (AM1.5G) was achieved in a 1 cm/sup 2/ photovoltaic cell, designed for tandem or thermophotovoltaic (TPV) application. Under concentrated sunlight (200-250/spl times/) a 0.13 cm/sup 2/ GaSb cell reached an efficiency of 9.9%.