High Sensitive and Broadband Photodetectors Based on Hybrid PbI₂ Nanosheet/CdSe Nanobelt

Abstract

The limited detection of lead iodide (PbI2) to visible light hinders the further development of PbI2 in the field of optoelectronic applications. A photodetector based on PbI2 nanosheet/CdSe nanobelt (PbI2 NS/CdSe NB) is prepared for the first time. This composite structure exhibits broadband spectral photoresponse from ultraviolet (400 nm) to red (730 nm). More importantly, PbI2 NS/CdSe NB can promote the effective separation of electron–hole pairs and improve the photoelectric performance. Compared to single PbI2 NS, the PbI2 NS/CdSe NB photodetector exhibits higher light–dark current ratio (6.778 × 103 A), responsivity (347.57 A W−1), and detectivity (3.625 × 1015 Jones) under 490 nm illumination. A new strategy is provided here to design broadband and high‐performance photodetectors.

Flexible Omnidirectional Self-Powered Photodetectors Enabled by Solution-Processed Two-Dimensional Layered PbI2 Nanoplates

“…The experimental values of the band gap can be obtained through a Kubelka–Munk transformation of the UV–vis spectra: [ F ( R ) h ν] 2 , where F ( R ) is the diffuse reflectance spectrum, h is Planck constant, ν is the frequency . The calculated band gap of PbI 2 nanoplates is about 2.36 eV (Figure d, Inset), which is in good agreement with previous reports. , Based on the above discussion, the large size PbI 2 nanoplates are successfully prepared on transparent conducting glasses using a facile and low-cost solution method.…”

“…The morphology of as-prepared PbI 2 nanoplates is characterized by scanning electron microscopy (SEM), showing a relatively flat surface except for some tiny island-shaped nanocrystals (Figure S1a). This phenomenon can also be observed in other solution-processed PbI 2 nanoplates. , The thickness of 2D PbI 2 nanoplates has been characterized by atomic force microscopy (AFM) and the average thickness of 2D PbI 2 nanoplates is 81.6 ± 4.8 nm (Figure S1b, c). To verify the crystal quality, the crystal structure of the prepared PbI 2 nanoplates is further investigated.…”

“…PbI 2 is selected for constructing self-powered photodetectors because it is one of the most investigated solution-processed photoelectric materials . As displayed in Figure a, b, the PbI 2 nanoplates prepared using the solution method show triangle and hexagon morphology on ITO and FTO.…”

“…■ RESULTS AND DISCUSSION PbI 2 is selected for constructing self-powered photodetectors because it is one of the most investigated solution-processed photoelectric materials. 16 As displayed in Figure 1a, b, the PbI 2 nanoplates prepared using the solution method show triangle and hexagon morphology on ITO and FTO. The morphology of as-prepared PbI 2 nanoplates is characterized by scanning electron microscopy (SEM), showing a relatively flat surface except for some tiny island-shaped nanocrystals (Figure S1a).…”

“…This phenomenon can also be observed in other solutionprocessed PbI 2 nanoplates. 16,17 The thickness of 2D PbI 2 nanoplates has been characterized by atomic force microscopy (AFM) and the average thickness of 2D PbI 2 nanoplates is 81.6 ± 4.8 nm (Figure S1b, c). To verify the crystal quality, the crystal structure of the prepared PbI 2 nanoplates is further investigated.…”