High detectivity PbSxSe1-x films for mid-wavelength infrared detectors

THIN SOLID FILMS

卷:731

Article

Maksimov, O.¹  Su, P.²  Bhattacharya, P.¹  Stoll, K. E.²  Wada, K.²  Kimerling, L. C.²  Agarwal, A.^2,3  Bhandari, H. B.¹ 

[1] Radiat Monitoring Devices Inc, Watertown, MA 02472 USA

[2] MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA

[3] MIT, Mat Res Lab, Cambridge, MA 02139 USA

关键词: Lead chalcogenide ternary alloys;    Infrared detectors;    Physical vapor deposition;    Detectivity;    Microstructure;    Grain boundary;   

DOI  :  10.1016/j.tsf.2021.138749

来源: Elsevier

【 摘 要 】

Lead salt detectors consisting of PbSe-PbS alloys offer detection capability in the 3-5 mu m midinfrared wavelength range and exhibit responsivity at near-room temperature conditions. In this paper, we present the growth of PbSe0.6S0.4 layers by physical vapor deposition and evaluate their properties and performance as a function of the deposition temperatures (50 degrees C and 200 degrees). Specifically, the influences of deposition temperature on the microstructure of PbSe0.6S0.4 and its subsequent detectivity is evaluated. The high temperature growth at 200 degrees C results in films with the near-columnar fiber-like microstructure; low temperature growth at 50 degrees C results in films with the fine equiaxed grains. Importantly, reduction of the growth temperature leads to a better photoresponse (up to two orders of magnitude) following the O2 sensitization of the PbSe0.6S0.4 films. We attribute this improvement to the more effective oxidation process due to a large increase in the density of the grain boundaries as a result of a smaller grain size.

【 授权许可】

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