Optimized Si-Based Blocked Impurity Band Detector Under Alternative Operational Mode

Abstract

In this paper, alternative operational mode (AOM) of Si-based blocked impurity band (BIB) detectors is thoroughly investigated. The basic structure of the detector evolves from the prototype of the ion-implanted BIB detector, which is potentially compatible with CMOS processes. Benefiting from lower dark current, the detectivity of ion-implanted devices studied in this work is comparable with the Si BIB detectors ever reported. For ion implantation devices, a peak blackbody detectivity of ${5} \times {10}^{{12}}$ cm $\cdot $ Hz ^1/2 /W (background temperature T = 40 K) occurs at 2 V under AOM. These merits make the ion-implanted device a powerful candidate for a wide range of applications from infrared to terahertz band. By analyzing the carrier distribution and the band structure in different functional regions of the device at the measured temperature, depletion junction formed in the region of active layer near active layer/cathode interface side is deduced when the device is operated under AOM. The theory is successfully used to interpret experimental data, including the detectivity comparable to the epitaxial device, significantly reduced dark current.