Fabrication of lead telluride quantum dots and their application in photoelectrochemical-type photodetectors

Abstract

IV-VI semiconductors have been extensively applied in photo-electrochemical (PEC)-type photodetectors. However, electrolytes with relatively high concentrations have been addressed which could induce electrochemical reactions during the measurement and result in a performance decrement. In this work, lead telluride quantum dots (PbTe QDs) with uniform size distribution are fabricated for PEC-type photodetectors and their performance is systematically investigated in electrolytes with concentrations as low as 10−4 mol/L. As revealed, the PbTe QD-based photodetectors show apparent photo-response with excellent stability in 1000 cycles (decrement of 0.018 % per cycle). In addition, the as-fabricated photodetectors show a broadband response to light in a region of 350–700 nm. These results are well supported by density functional theory calculations based on structural features and electronic and optical properties. Hence, we envisage that this work paves the way to fabricate high-performance photodetectors in relatively low-concentration electrolytes, which also can extend their applications to other optoelectronic devices.