Antimonide-based devices for thermophotovoltaic applications

Thermophotovoltaic (TPV) devices have been fabricated using ternary and quaternary layers grown by metalorganic vapor phase epitaxy (MOVPE) on GaSb substrates. GaInSb ternary devices were grown with buffer layers to accommodate the lattice mismatch, and GaInAsSb quaternary devices were grown with lattice-matched compositions. Improved devices are obtained when optical absorption occurs in the p-layer due to the longer minority carrier diffusion length. Thick emitter p/n devices are limited by surface recombination, with highest quantum efficiency and lowest dark current being achieved with epitaxially grown surface passivation layers on lattice-matched MOVPE quaternaries. Thin emitter/thick base, n/p devices are very promising since surface passivation is less critical than for p-emitter devices