GaSb Based PV Cells with Zn-Diffused Emitters

The paper presents the results of the development of GaSb cells, manufactured for tandem solar cells and designed for point and line-focus concentrator modules. The cells based on GaSb homo-junctions, Zn-diffused structures have been developed for thermophotovoltaic (TPV) applications as well. The maximum efficiency of 11.3% (AMO) was achieved in GaSb cells for 70 suns concentration. The TPV devices with band gap of 0.55 eV were fabricated on the basis of the GaSb/InGaAsSb structures. The photocurrent density of 58mA/cm 2 has been measured under AMO I sun illumination. Secondly, two-terminal monolithic GaSb(top)/InGaAsSb(bottom) tandem thermophotovoltaic devices with internal tunnel junction have been designed and fabricated. External quantum yields of 80-85 % in the top cell and of 75-80% in the bottom cells have been measured. A high photoresponse in the wavelength range of λ=700-2150 nm, as well as V oc =0.60 V and FF=0.75 at the photocurrent density of 0.70 A/cm 2 were achieved in these tandems.