Towards an AlGaN, solar-blind, p-i-n photodetector

A heterostructure diode, utilizing p- and i-Al0.33Ga0.67N layers on top of an n-GaN region, is investigated for its-potential as a solar-blind photode tector. The study, which is carried out via simulations using MEDICI, exami nes some techniques for suppressing the hole current-that is photogenerated in the low bandgap n-GaN material. The factors considered are: the: thickn ess and electron affinity of the i-Al0.33Ga0.67N layer; the addition of a t hin, n-doped AlGaN layer to widen the tunneling barrier for holes; and the creation of a thin region of low minority carrier lifetime at the heteroint erface to remove the holes by recombination. The results show that AlGaN/Ga N, p-i-n heterodiodes have considerable promise as solar-blind photodetecto rs.