Lateral PbS Photovoltaic Devices for High Performance Infrared and Terahertz Photodetectors

Abstract

We fabricated a lateral photovoltaic device for use as infrared to terahertz (THz) detectors by chemically depositing PbS films on titanium substrates. We discussed the material properties of PbS films grown on glass with varying deposition conditions. PbS was deposited on Ti substrates and by taking advantage of the Ti/PbS Schottky junction, we discussed the photocurrent transients as well as the room temperature spectrum response measured by Fourier transform infrared (FTIR) spectrometer. Our photovoltaic PbS device operates at room temperature for wavelength ranges up to 50 µm, which is in the terahertz region, making the device highly applicable in many fields.

Temperature dependence of infrared photoresponse from lead sulfide film grown by chemical bath deposition

“…Most previous research has focused on the use of PbS in photoconductive infrared detectors, but its narrow bandgap results in high dark current and background noise, whereas photovoltaic PbS infrared detectors can suppress dark current and therefore get lots of attentions. Photovoltaic devices that do not require external bias have plenty of advantages such as negligible dark current, low noise, and fast response [9].…”