Design of uncooled mid-wave infrared detectors based on lead selenide barrier structure
Mid- and long-wavelength IR photodetectors incorporating narrow-bandgap semiconductors often face the challenge of large RT dark current, limiting their applications in military and civilian use. Herein, a novel pBn+ barrier detector architecture based on a lead selenide/indium selenide barrier structure is proposed to significantly suppress the dark current, so that uncooled mid-wave IR (MWIR) photodetectors with high performance can be achieved. The finite element analysis of the detector demonstrates reduced RT dark current down to 55 mA cm−2 under −0.1 V bias, which is a two-fold decrease compared to the InAs/InAsAb type-II superlattice detector. In addition, at RT, the optimized pBn+ barrier detector exhibits excellent responsivity and detectivity of 1.23 A W−1 and 9.47 × 109 cm Hz1/2·W−1 at 3.8 μm, respectively. The PbSe-based barrier architecture provides a promising industrialization solution for high-performance uncooled MWIR photodetectors.
