Recent progress in InGaAsSb/GaSb TPV devices

Conference · Wed May 01 04:00:00 EDT 1996

OSTI ID:296773

Shellenbarger, Z A; Mauk, M G; DiNetta, L C ^[1]; Charache, G W ^[2]

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1. AstroPower, Inc., Newark, DE (United States)
2. Lockheed Martin Corp., Schenectady, NY (United States)

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{sub 1{minus}x}Ga{sub x}As{sub 1{minus}y}Sb{sub 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 1,000 to 1,500 C thermal sources with, at the same 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. 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/cm{sup 2} is 0.220 volts and 0.280 V for current densities of 2 A/cm{sup 2}. Fill factors of 56% have been measured at 60 mA/cm{sup 2}. However, as current density increases there is some decrease in fill factor. The results to date show that the GaSb-based quaternary compounds provide a viable and high performance energy conversion solution for thermophotovoltaic systems operating with 1,000 to 1,500 C source temperatures.

• Research Organization: Knolls Atomic Power Lab., Schenectady, NY (United States)
• Sponsoring Organization: USDOE Assistant Secretary for Nuclear Energy, Washington, DC (United States)
• DOE Contract Number: AC12-76SN00052
• OSTI ID: 296773
• Report Number(s): KAPL-P--000047; CONF-9605348--; ON: DE99000437
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
DESIGN
GALLIUM ANTIMONIDES
GALLIUM ARSENIDES
INDIUM ANTIMONIDES
INDIUM ARSENIDES
PERFORMANCE
QUANTUM EFFICIENCY
SEMICONDUCTOR MATERIALS
TEMPERATURE RANGE 1000-4000 K
THERMOPHOTOVOLTAIC CONVERTERS