High‐Performance Te‐Doped PbSe Film Heterojunction Photodetector with Current Rectification Effect and Broadband Detection Capability

Abstract

PbSe has attracted wide attention owing to its fascinating physical and chemical properties. It has important technical significance for infrared detectors. However, due to the inherent bandgap, low carrier mobility, and dielectric constant of PbSe, it is a significant challenge to realize fast response and mid‐infrared (MID) photodetection. Chemical doping is an efficient method to regulate the band structure and carrier mobility of materials. Nevertheless, the doped film detector cannot satisfy the demands of high‐performance photodetectors. In this paper, different composition ratios powders are synthesized by a solid‐state method. The PbSe0.5Te0.5 alloy film displays narrower bandgap, higher carrier mobility, excellent photo‐response, and broadband detection capacity. By utilizing the above superiority of PbSe0.5Te0.5 and fast charge transfer in MoSe2, a PbSe0.5Te0.5/MoSe2 p‐n heterostructure device is successfully fabricated that has significant rectifying effect (103) and extremely low dark current density (720 µA cm−2). The photodetector has a maximum responsivity (R) and specific detectivity (D*) of 17.5 A W−1 and 3.08 × 1013 Jones at 780 nm. In addition, the detector displays superior photodetection performance with broadband photodetection (405–5000 nm), high switch ratios (Ion/Ioff = 105), and fast response speed. The above outstanding properties indicate that the PbSe0.5Te0.5/MoSe2 heterostructure provides a promising and efficient strategy for achieving a miniaturized, broadband, and high‐performance photodetector.

Environmental-Friendly Ag2S QD-Multilayer MoSe2 van Der Waals Heterostructure for High-Performance Broadband Photodetection

“…According to the above equation, the calculated W F of Ag 2 S QDs is 3.5 eV. Also, the W F of the multilayered MoSe 2 was reported to be at around 4.2 eV in the previous reports. , Additionally, the band gaps of multilayer MoSe 2 and Ag 2 S QDs were 1.1 and 0.9 eV, respectively. , The band energy alignment before contact is shown in Figure S3b, and a typical type-II energy-band alignment for MoSe 2 and Ag 2 S QDs was formed. Owing to the difference of work function in MoSe 2 and Ag 2 S QDs, the electrons of Ag 2 S QDs would transfer to MoSe 2 until an equilibrium state is achieved at the interface.…”

“…Also, the W F of the multilayered MoSe 2 was reported to be at around 4.2 eV in the previous reports. 27,28 Additionally, the band gaps of multilayer MoSe 2 and Ag 2 S QDs were 1.1 and 0.9 eV, respectively. 35,41 The band energy alignment before contact is shown in Figure S3b, and a typical type-II energy-band alignment for MoSe 2 and Ag 2 S QDs was formed.…”

“…26 Wang et al reported a 2D/2D van der Waals heterostructure based on MoSe 2 / PbSe 0.5 Te 0.5 , and the device has a photodetection range from visible to mid-infrared (0.4−5 μm), as well as a maximum responsivity of ∼17.5 A/W at a wavelength of 780 nm. 27 In addition, Gao et al reported a MoSe 2 /Bi 2 O 2 Se nanowire (2D/ 1D) NIR photodetector with a high rectification ratio of 10 3 , within the wavelength range of 405−808 nm. 28 However, due to the complicated interfaces, the complex manufacturing process, and the enhanced Auger scattering processes, 29−31 the devices based on 2D/3D, 2D/2D, and 2D/1D heterostructure still face performance limitation and a low yield of fabrication, which severely hinders their further application in the field of high-performance optoelectronics.…”

“…Constructing van der Waals heterostructure is a promising technique that can combine the features of different materials to improve the photodetector performance , and offers a vast opportunity for realizing high-performance electronic and optoelectronic devices. Recently, MoSe 2 -based van der Waals heterostructures for broadband photodetection have been reported, which integrate MoSe 2 with one-dimensional (1D) nanowires, 2D materials, and three-dimensional (3D) films to enhance the photodetection performance. − For instance, Das et al combined MoSe 2 and 3D Ge to realize a 2D/3D van der Waals heterostructure-based photodetector with a broadband response over 400–1800 nm, which showed a good responsivity of 24 A/W under 750 nm . Wang et al reported a 2D/2D van der Waals heterostructure based on MoSe 2 /PbSe 0.5 Te 0.5 , and the device has a photodetection range from visible to mid-infrared (0.4–5 μm), as well as a maximum responsivity of ∼17.5 A/W at a wavelength of 780 nm .…”

“…Recently, MoSe 2 -based van der Waals heterostructures for broadband photodetection have been reported, which integrate MoSe 2 with one-dimensional (1D) nanowires, 2D materials, and three-dimensional (3D) films to enhance the photodetection performance. − For instance, Das et al combined MoSe 2 and 3D Ge to realize a 2D/3D van der Waals heterostructure-based photodetector with a broadband response over 400–1800 nm, which showed a good responsivity of 24 A/W under 750 nm . Wang et al reported a 2D/2D van der Waals heterostructure based on MoSe 2 /PbSe 0.5 Te 0.5 , and the device has a photodetection range from visible to mid-infrared (0.4–5 μm), as well as a maximum responsivity of ∼17.5 A/W at a wavelength of 780 nm . In addition, Gao et al reported a MoSe 2 /Bi 2 O 2 Se nanowire (2D/1D) NIR photodetector with a high rectification ratio of 10 3 , within the wavelength range of 405–808 nm .…”