In Situ Growth of PbS/PbI2 Heterojunction and Its Photoelectric Properties

Abstract

In this paper, PbI2 thin films with a uniform surface morphology and compact structure were prepared by adjusting the spin coating process parameters. On such a basis, the PbS/PbI2 heterojunction was fabricated on the PbI2 surface by the method of in situ chemical replacement growth. The results show that the PbS/PbI2 heterojunction grown by this method has a clear interface and is closely combined. The introduction of a PbS layer enables its spectral response range to cover the visible and near-infrared regions. Compared with the PbI2 thin film device, its responsivity is increased by three orders of magnitude, its response time reduced by 42%, and its recovery time decreased by nearly 1/2 under 450 nm illumination. In the case that there is no response for the PbI2 thin film device under 980 nm illumination, the specific detectivity of the PbS/PbI2 heterojunction device still amounts to 1.8 × 108 Jones. This indicates that the in situ chemical replacement is a technique that can construct a high-quality heterojunction in a simple process. PbS/PbI2 heterojunction fabricated by this method has a visible–near-infrared light detection response range, which provides a new idea for creating visible–near-infrared common-path detection systems.

Tuning Performance of Heterojunction Flexible Photodetectors by Energy Band Alignment Engineering

“…Although numerous studies have explored the positive effects of various dopants such as MoSe 2 , ZnO, SbSI, Gd, Au, Nd, PbS MoS 2 , WS 2 , and GO on enhancing the optoelectronic properties of PbI 2 heterostructure. Instead of focusing on binary n-type semiconductors (such as CdS, CdSe) of group II–VI elements, we opt for low-cost multicomponent alloyed CdS x Se 1– x because it exhibits a well-tailored bandgap (covering almost the entire range of group II–VI elements) by precisely governing the stoichiometric ratio and thereof has been extensively probed due to its abundance and promising long-term stable device performance .…”

Semiconductor–Semimetal Transition‐Driven Photocurrent Spurt and Infrared Band Response in Lead Iodide at High Pressure

“…For example, the drawback of zero bandgap graphene, the instability of black phosphorus under ambient conditions, and the oversized bandgap of most TMDs limit the spectral response range, which restricts their practical applications. [6,8,20] Recently, the appearance of 2D heterostructures composed of different materials further promoted infrared photodetection devices, [26,27] despite the complicated process of fabricating heterojunctions and the limited size of devices. Therefore, constantly developing novel materials to achieve a broad waveband response and high photoelectric performance as ideal photodetectors is of great importance.…”