InGaAsSb/GaSb thermophotovoltaic cells

Conference · Sun Oct 01 04:00:00 EDT 1995

OSTI ID:177666

Mauk, M G; Dinetta, L C; Shellenbarger, Z A

AstroPower is developing InGaAsSb thermophotovoltaic (TPV) devices. This photovoltaic cell is a two-layer epitaxial InGaAsSb structure formed by liquid-phase epitaxy on a GaSb substrate. The (direct) bandgap of the In(1 {minus} x)Ga(x)As(1 {minus} y)Sb(y) alloy is 0.50 to 0.55 eV, depending on its exact alloy composition (x,y); and is closely lattice-matched to the GaSb substrate The use of the quaternary alloy, as opposed to a ternary alloy - such as, for example, InGaAs/InP - permits low bandgap devices optimized for 1000 to 1500 C thermal sources, with at the time, near-exact lattice matching to the GaSb substrate. Lattice-matching is important since even a small degree of lattice mismatch degrades device performance and reliability and increases processing complexity. For bandgaps of 0.52 eV, Fo internal quantum efficiencies as high as 95% have been measured at a wavelength of 2 microns. At 1 micron wavelengths, internal quantum efficiencies of 55% have been observed. The open-circuit voltage at currents of 0.3 A/sq cm is 0.220 volts and 0.260 V for current densities of 2 A/sq cm. Fill factors of 56% have also been measured. These preliminary results lead to the conclusion that the GaSb-based quaternary compounds provide a viable and high performance energy conversion solution for thermophotovoltaic systems operating with 1000 to 1500 C source temperatures.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center
• OSTI ID: 177666
• Report Number(s): N--96-15042; NASA-CP--10180; NAS--1.55:10180; E--9943; NIPS--95-05337; CONF-9510288--
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
ARSENIC COMPOUNDS
CURRENT DENSITY
EPITAXY
GALLIUM ANTIMONIDES
INDIUM ANTIMONIDES
QUANTUM EFFICIENCY
QUATERNARY COMPOUNDS
THERMOPHOTOVOLTAIC CONVERTERS