GaSb Applications for Solar Thermophotovoltaic Conversion

GaSb based structures were developed and fabricated by the Zn-diffusion technique for thermophotovoltaic applications. Investigation of characteristics of cells for a conical system was carried out under a flash tester. Outdoor measurements of an array of three GaSb cells connected in parallel in a cylindrical system were carried out under illumination from tungsten emitters of different lengths. The maximum cylindrical system array photocurrent of 3.5 A has been obtained at the tungsten emitter temperature of 1400 deg C. An optimum Zn diffused profile and penetration depth of p-n junction have been found, which allowed to obtain the maximum efficiency of GaSb cells at high generated photocurrent density of up to 5 A/cm2. Study of the doping profile and characteristics of GaSb cells fabricated by means of a non-traditional diffusion - from a solid state film diffusant - was performed as well. The external quantum yield of these cells was 0.82-0.87 at wavelength range of 800-1600 nm.