Metal-organic chemical vapour deposition growth of InAs/GaSb type-II superlattice photodiodes

Presented for the first time is the realisation of InAs/GaSb type-II superlattice photodiodes grown by metal-organic chemical vapour deposition. The photovoltaic detectors have a cutoff wavelength (50% power responsivity) of ~8 μm at 78 K. The active region was grown on a p-type GaSb substrate and consists of an InAs(5.1 nm)/ GaSb(2.1 nm) superlattice. The R₀4 product is typically around 0.03 Ω-cm² at 78 K. The responsivity is typically around 0.6 A/W and the detectivity is 1.6 × 109 at 78 K.