Highly Efficient, Ultrabroad PdSe₂ Phototransistors from Visible to Terahertz Driven by Mutiphysical Mechanism

Abstract

The noble transition metal dichalcogenide palladium diselenide (PdSe2) is an ideal candidate material for broad-spectrum photodetection owing to the large bandgap tunability, high mobility, low thermal conductivity, and large Seebeck coefficient. In this study, self-powered ultrabroadband PdSe2 photodetectors from the visible–infrared to terahertz (THz) region driven by a mutiphysical mechanism are reported. In the visible–infrared region, the photogenerated electron–hole pairs in the PdSe2 body are quickly separated by the built-in electric field at the metal–semiconductor interface and achieve a photoresponsivity of 28 A·W–1 at 405 nm and 0.4 A·W–1 at 1850 nm. In the THz region, PdSe2 photodetectors display a room-temperature responsivity of 20 mA·W–1 at 0.10 THz and 5 mA·W–1 at 0.24 THz based on efficient production of hot carriers in an antenna-assisted structure. Owing to the fast response speed of ∼7.5 μs and low noise equivalent power of ∼900 pW·Hz–1/2, high-resolution transmission THz imaging is demonstrated under an ambient environment at room temperature. Our research validates the great potential of PdSe2 for broadband photodetection and provides a possibility for future optoelectronic applications.

Recent advances in TMD interfaces with seamless contacts

“…Mo-based TMDs consist of Mo layers sandwiched between two chalcogen layers. 1,2 TMDs exist in different phases such as 2H and 1T 0 as shown in Fig. 1(a and b).…”

“…Two-dimensional (2D) transition metal dichalcogenides (TMDs) can have a wide range of compositions and dual phases of crystalline and electronic structures, giving these materials a wide range of interesting properties. [1][2][3][4][5][6][7][8][9][10][11][12] The number of layers has a significant influence on the physical properties of the materials as well as defining the electrical and optical structures of 2D quantum systems due to quantum confinement and interlayer interactions. Because of their various layered structures, such as hexagonal 2H polytype to semimetal (trigonal 1T 0 polytype) phases and distorted octahedral, the number of layers has a significant impact on the physical material characteristics.…”

Terahertz modulation characteristics of three nanosols under external field control based on microfluidic chip

“…Because of their wide bandwidth, low photon energy, and fingerprint spectral properties, THz waves have a wide range of application prospects in basic research fields, such as wireless communication, medical imaging, and biological diagnosis ( Li et al., 2022 ; Jia et al., 2022 ; Dong et al., 2022 ; Wang et al., 2022a , 2022b , 2022c ). Recently, THz sources ( Dong et al., 2021 ) and THz detectors ( Asgari et al., 2021 ) have made great progress, and solid-state THz modulation elements have developed rapidly with the increasing maturity of metasurface technology and semiconductor theory. Based on a Si/VO 2 hybrid metasurface, Zhao et al.…”

Waveguide-Integrated PdSe2 Photodetector over a Broad Infrared Wavelength Range

“…The experimental results (Figure C) demonstrate a completely open eye at 3 V with a data rate of 2.5 Gbit·s –1 . Overall, the proposed PdSe 2 photodetectors show apparent advantages compared with photodetectors based on VDW semiconductors (Figure D), ,,,− and the detailed comparison is listed in Supporting Information.…”