Craig, Adam and Reyner, Charles J. and Marshall, Andrew and Huffaker, Diana L. (2014) Excess noise in GaAs and AlGaAs avalanche photodiodes with GaSb absorption regions—composite structures grown using interfacial misfit arrays. Applied Physics Letters, 104. ISSN 0003-6951
Abstract
Interfacial misfit arrays were embedded within two avalanche photodiode (APD) structures. This allowed GaSb absorption layers to be combined with wide-bandgap multiplication regions, consisting of GaAs and Al0.8Ga0.2As, respectively. The GaAs APD represents the simplest case. The Al0.8Ga0.2As APD shows reduced dark currents of 5.07 μAcm−2 at 90% of the breakdown voltage, and values for effective below 0.2. Random-path-length modeled excess noise is compared with experimental data, for both samples. The designs could be developed further, allowing operation to be extended to longer wavelengths, using other established absorber materials which are lattice matched to GaSb.