High-operating temperature InAsSb/AISb heterostructure infrared detectors

摘要

An InAsSb/AISb heterostructure photovoltaic detector structures were grown on a (100) semi-insulating GaAs substrates by a molecular beam epitaxy. We compare the performance of two detectors with a different type of absorbing layers, denoted p~+B_ppB_pn~+ and p~+B_pnn~+. InAs_(0.81)Sb_(o.19) absorption layers allow for a operation up to 5.3 u,m cut-off wavelengths at 230 K. p+Bpnn+ detector (n-type absorber) exhibits diffusion-limited dark currents above 200 K. AlSb barrier provides a low values of dark currents and allows a suppression of surface leakage current. With a value of 0.13 A/cm~2 at 230 K, the current is less than an order of magnitude larger than those determined by the "Rule 07" for HgCdTe detectors. Dark currents of p~+B_ppB_pN~+ detector (p-type absorber) are much higher due to a contribution of Shockley-Read-Hall mechanisms. On the other hand, device with a p-type absorber shows highest values of current responsivity, up to 2.5 A/W, point out that there is a trade-off between dark current performance and quantum efficiency.