Kim, Jungdong Ampadu, Emmanuel K. Oh, Eunsoon Choi, Hongkyw Ahn, Hak-Young Cho, So-Hye Choi, Won Jun Byun, Ji Young 2024-01-19T18:02:24Z 2024-01-19T18:02:24Z 2021-09-05 2020-03 1567-1739 https://pubs.kist.re.kr/handle/201004/118894 We discussed photocurrent spectra of photovoltaic PbS infrared detectors using multi-layer graphene as transparent electrode, where p-PbS films were deposited on TiO2/FTO substrates by chemical bath deposition. In the photocurrent spectra, we observed both above-bandgap and sub-bandgap photocurrent without any external bias. We discussed impurity band model and grain boundary model in order to explain the sub-bandgap photocurrent near 15 mu m. Since FTO is transparent in the visible range, we were able to illuminate green laser beam from the FTO back-side, and photo-response up to 50 mu m was found to be enhanced. This long wavelength photo-response was attributed to the excitation of the photo-electrons accumulated at the TiO2/PbS interface. Our photovoltaic PbS devices can detect not only short-infrared but also terahertz radiation at room temperature, which is highly applicable to various fields. English ELSEVIER TRANSPORT LAYER QUANTUM DOTS Photocurrent spectra for above and below bandgap energies from photovoltaic PbS infrared detectors with graphene transparent electrodes Article 10.1016/j.cap.2020.01.006 1 CURRENT APPLIED PHYSICS, v.20, no.3, pp.445 - 450 CURRENT APPLIED PHYSICS 20 3 445 450 scie scopus kci ART002569504 000509752300012 2-s2.0-85077753460 Materials Science, Multidisciplinary Physics, Applied Materials Science Physics Article TRANSPORT LAYER QUANTUM DOTS Lead sulfide Photocurrent spectra Infrared detectors Photovoltaic Multilayer graphene