Optimisation of InGaAs infrared photovoltaic detectors

The ultimate signal-to-noise performance of infrared photodetectors is limited by the statistical nature of the thermal generation and recombination of charge carriers. Band-to-band Auger processes dominate in a high quality InGaAs used for photovoltaic detector operating at room temperature. The performance of devices operating in the 2-3.4 μm spectral range has been analyzed theoretically. Homo- and heterostructure devices have been considered. The use of n⁺np⁺ (or n⁺pp⁺) with heavily doped regions has been found to prevent the recombination of photogenerated carriers at contacts, but the bulk thermal generation in the heavily doped regions will significantly reduce the performance of the devices