Ternary and quaternary antimonide devices for thermophotovoltaic applications

Thermophotovoltaic (TPV) devices have been fabricated using epitaxial terna ry and quaternary layers grown on GaSb substrates. GaInSb ternary devices w ere grown by metalorganic vapor-phase epitaxy (MOVPE) with buffer layers to accommodate the lattice mismatch, and GaInAsSb lattice-matched quaternarie s were grown by MOVPE and by liquid-phase epitaxy (LPE). Improved devices a re obtained when optical absorption occurs in the p-layer due to the longer minority carrier diffusion length. Thick emitter p/n devices are limited b y surface recombination, with highest quantum efficiency and lowest dark cu rrent being achieved with epitaxially grown surface passivation layers on l attice-matched MOVPE quaternaries. Thin emitter/thick base n/p devices are very promising, but require improved shallow high-quality n-type ohmic cont acts. (C) 1998 Elsevier Science B.V. All rights reserved.