Highdetectivity AlInSb Midinfrared Photodiode Sensors with Dislocation Filter Layers for Gas Sensing

Abstract

A midinfrared photodiode is developed for methane gas sensing based on the highly mismatched AlInSb/GaAs system. Inserting optimized dislocation filter layers (DFLs) in the buffer layer reduced the threading dislocation density in the active layer to less than one-third of that in the photodiode without DFLs. This improvement produces a high normal incidence detectivity of 1.8 Â 10 9 cm p Hz W À1 at 3.3 μm, which is more than twice the highest detectivity previously obtained for a photodiode without DFLs. Conflict of InterestThe authors declare no conflict of interest.

R-branch high-lying transition emission spectra of SbNa molecule*

“…[1] Antimony compounds play a significant role in the chemical industry and electronic industry. [2][3][4][5] For instance, the antimony-sodium (SbNa) not only has a lowcost and simple preparation process, but also possesses a short response time and high sensitivity in the visible and near-infrared range, thus becoming one of the concerned photocathode materials. [6,7] However, uncertainties of the exact structure and physical mechanism bring the difficulty into theoretical guidance of manufacturing technique, which leads to over reliance on past experience in the production, thereby limiting the improvement of its performance.…”