High-efficiency (49%) and high-power photovoltaic cells based on gallium antimonide

High-efficiency GaSb-based photovoltaic cells designed for conversion of high-power laser radiation and infrared radiation of emitters heated by concentrated solar radiation are fabricated and studied. The maximum efficiency of conversion of the radiation with λ = 1680 nm was 49% at the photocurrent density of 50–100 A/cm2 for the fabricated photovoltaic cells. The methods for reducing the losses at ohmic contacts to p-and n-GaSb are investigated. The minimum values of the specific resistance, (1–3) × 10−6 Θ cm2, of contact to p-GaSb with the doping level of 1020 cm−3 were obtained using the Ti/Pt/Au contact system. The minimum values of the specific contact resistance were (1–3) × 10−6 Θ cm2 in the case of n-GaSb with the doping level of 2 × 1018 cm−3 if the Au(Ge)/Ni/Au and Au/Ni/Au contact systems are used.