Rear illumination monolithically integrated GaSb thermophotovoltaic devices grown on semi-insulating GaAs substrate

This paper presents the device design, modeling, materials growth, and device fabrication results of wafer scale monolithically integrated modules (MIMs) of series interconnected GaSb thermo-photovoltaic (TPV) cells grown on 50 mm diameter semi-insulating (SI) GaAs substrates. The feasibility of using GaSb epi-layers grown on SI GaAs for fabricating modules of photovoltaic (PV) cells connected in series for the conversion of low temperature heat radiating sources into electrical energy has been demonstrated. Device modeling shows that assuming an Shockley-Read-Hall recombination lifetime of 100 ns, in addition to intrinsic radiative and Auger recombination in GaSb, it is possible to design PV cells that when placed at sub-micron distance from a 900 °C radiating source are able to convert the heat into electrical energy at a power density of 1.5 to 3 W/cm2 using GaSb epi-layers grown on SI GaAs. The advantage of using SI GaAs is that it is possible to produce MIM modules of PV cells that can have output vo...