Cds/Pbse Heterojunction For High Temperature Mid-Infrared Photovoltaic Detector Applications

n-CdS/p-PbSe heterojunction is investigated. A thin CdS film is deposited by chemical bath deposition on top of epitaxial PbSe film by molecular beam epitaxy on Silicon. Current-voltage measurements demonstrate very good junction characteristics with rectifying ratio of similar to 178 and ideality factor of 1.79 at 300 K. Detectors made with such structure exhibit mid-infrared spectral photoresponse at room temperature. The peak responsivity R-lambda and specific detectivity D* are 0.055 A/W and 5.482 x 10(8) cm.Hz(1/2)/W at lambda = 4.7 mu m under zero-bias photovoltaic mode. Temperature-dependent photoresponse measurements show abnormal intensity variation below similar to 200 K. Possible reasons for this phenomenon are also discussed. (C) 2014 AIP Publishing LLC.