Promoted Mid-Infrared Photodetection of PbSe Film by Iodine Sensitization Based on Chemical Bath Deposition

Abstract

In recent years, lead selenide (PbSe) has gained considerable attention for its potential applications in optoelectronic devices. However, there are still some challenges in realizing mid-infrared detection applications with single PbSe film at room temperature. In this paper, we use a chemical bath deposition method to deposit PbSe thin films by varying deposition time. The effects of the deposition time on the structure, morphology, and optical absorption of the deposited PbSe films were investigated by x-ray diffraction, scanning electron microscopy, and infrared spectrometer. In addition, in order to activate the mid-infrared detection capability of PbSe, we explored its application in infrared photodetection by improving its crystalline quality and photoconductivity and reducing tge noise and high dark current of PbSe thin films through subsequent iodine treatment. The iodine sensitization PbSe film showed superior photoelectric properties compared to the untreated sample, which exhibited the maximum of responsiveness, which is 30.27 A/W at 808 nm, and activated its detection ability in the mid-infrared (5000 nm) by introducing PbI2, increasing the barrier height of the crystallite boundary and carrier lifetimes. This facile synthesis strategy and the sensitization treatment process provide a potential experimental scheme for the simple, rapid, low-cost, and efficient fabrication of large-area infrared PbSe devices.

Self-Powered and Broadband Photodetector with High Responsivity and Fast Response Based on La-Doped PbSe Film Heterojunction

“…The photodetector efficiently detects and utilizes optical information by converting light signals into electrical signals, playing a crucial role in various fields such as science, industry, medicine, and communication. − PbSe, as a direct bandgap semiconductor, has a narrow bandgap typically ranging from 0.27 to 0.33 eV. , It is one of the most representative materials in lead chalcogenide semiconductors. Moreover, PbSe exhibits excellent optical absorption in the infrared spectrum due to its narrow bandgap making it widely applicable in the field of infrared photodetectors. − However, undoped PbSe semiconductors just have only a single conduct band contributing to the transport properties, leading to lower carrier concentrations and unsatisfactory electrical transport performance . Additionally, PbSe also faces limitations in high-performance and fast photodetector applications due to its larger dielectric constant and thermal expansion coefficient. , To overcome these inherent deficiencies and enhance its optical and electrical properties, it is necessary to find an efficient and convenient method.…”

“…The modulation techniques previously applied to PbSe include iodine sensitization, , oxygen sensitization, , preparation of PbSe-based composites, , synthesis of PbSe quantum dots, , and chemical doping . Among them, doping is an important and efficient strategy for optimizing the electrical and thermal transport properties of materials, improving carrier mobility, adjusting band structures, and overcoming intrinsic defects. , For instance, the carrier mobility of PbSe can be improved to 1006 cm 2 v −1 s −1 by Cr doping .…”