High Performance MWIR InAsSb-based nBn Photodetectors

Today with increasing the operating temperatures, obtaining the ability to reduce the dark current of MWIR photodetectors is obligated. In this paper, structures are considered based on InAsSb with Sb composition, xSb=0.17 as absorber layers with various barrier semiconductors to indicate the importance of using these nBnn structures in medical applications. We evaluate the impressive physical factors such as doping density of barrier layer and the applied bias voltage on the performance of these photodetectors to achieve two structures with desirable physical properties. Detailed analysis of barrier doping density confirms that n- type doping density ND<1xl014 cm−3 leads to valence band offset of less than 20 meV and makes it possible to estimate the high sensitivity of the proposed nBnn photodetectors. Also, the simulation results show that both structures have 92% and 99%, respectively reduction in dark current compared to the previous best structure.