Catalyst-free physical vapor deposition of crystalline PbSe nanosheets for fabrication of high-performance photodetector

Abstract

Influenced by the prominent progress of two-dimensional (2D) layered crystals, the fabrication of 2D nanostructures from non-layered materials has attracted more and more attention. Lead selenide (PbSe) is one of the superior candidate materials for photodetector with suitable bandgap and outstanding photoelectric properties. The growth and device preparation of PbSe supply great interest for the development of high-performance infrared photodetectors. Although a lot of efforts have been paid on preparing PbSe nanostructures for miniaturized detectors, it is challenging to synthesize excellent crystallinity and thin 2D PbSe nanosheets because of itsinherent rock salt nonlayered structure. In this work, we employ a catalyst-free facile physical vapor deposition (PVD) method for controllable synthesis of PbSe nanosheets by van der Waals epitaxy technology. By optimizing the growth temperature, PbSe nanosheets from triangular pyramid island to square 2D plane can be obtained. In addition, the 2D PbSe nanosheets detector has a responsivity of 3.03 A/W at the wavelength of 520 nm with the power density of 5.05 mW/cm2. This work provides a facile strategy to synthesize high-quality 2D PbSe nanosheets which have enormous potentials to fabricate high-performance miniaturized photodetector.