High-performance uncooled InAsSb-based pCBn mid-infrared photodetectors

Uncooled infrared photodetectors are essential for infrared technology that aims to provide low-cost, compact detection systems for widespread applications, which are particularly critical for the mid-wavelength and long-wavelength infrared photodetectors. In this work, by utilizing a compound barrier (CB) in a novel pCBn device design, we have demonstrated high performance InAs0.91Sb0.09 bulk absorber based mid-wavelength infrared (MWIR) photodetectors with a cut-off wavelength of around 4.8 mu m that can operate at a room temperature (RT) of 300 K. With nearly zero misalignment in the valence band with InAsSb absorber, this CB design can efficiently block the electrons while transit the holes, which greatly improves the optical response of the photodetectors. At 300 K, these photodetectors exhibit dark current density of 0.19 A/cm(2) at an operation bias of -450 mV. A saturated quantum efficiency at 4.3 mu m reaches similar to 57.5% and the peak responsivity reaches similar to 2.08 A/W, which yields a specific detectivity as high as 7.9 x 10(9) cm.Hz(1/2)/W.