Atomically thin noble metal dichalcogenide: a broadband mid-infrared semiconductor

Abstract

The interest in mid-infrared technologies surrounds plenty of important optoelectronic applications ranging from optical communications, biomedical imaging to night vision cameras, and so on. Although narrow bandgap semiconductors, such as Mercury Cadmium Telluride and Indium Antimonide, and quantum superlattices based on inter-subband transitions in wide bandgap semiconductors, have been employed for mid-infrared applications, it remains a daunting challenge to search for other materials that possess suitable bandgaps in this wavelength range. Here, we demonstrate experimentally for the first time that two-dimensional (2D) atomically thin PtSe2 has a variable bandgap in the mid-infrared via layer and defect engineering. Here, we show that bilayer PtSe2 combined with defects modulation possesses strong light absorption in the mid-infrared region, and we realize a mid-infrared photoconductive detector operating in a broadband mid-infrared range. Our results pave the way for atomically thin 2D noble metal dichalcogenides to be employed in high-performance mid-infrared optoelectronic devices.

Large‐Scale Ultrathin 2D Wide‐Bandgap BiOBr Nanoflakes for Gate‐Controlled Deep‐Ultraviolet Phototransistors

“…The D n * was calculated to be about 1.44 × 10 11 and 4.45 × 10 10 Jones (cm Hz 1/2 W −1 ), respectively, a bit lower than D * values obtained only considering I dark as the major source of short noise. Even so, the NEP and D n * based on 5 L BiOBr device are also much superior than those of the other reported 2D photodetectors considering noise current such as PdSe 2 (2.8 × 10 −13 W Hz −1/2 , 6 × 10 9 Jones)43 and PtSe 2 (7 × 10 8 Jones) 44. The excellent DUV detection capability of the BiOBr‐based photodetector has huge potential to realize high‐integration, high‐performance, low‐cost, and low‐power optoelectronic integrated circuit.…”

2D Metal Chalcogenides for IR Photodetection

“…The bilayer PtSe 2 phototransistor exhibits broadband response ranging from 632 nm to 10.0 µm and fast response rate in the millisecond as demonstrated in Figure d. Impressively, the PtSe 2 phototransistor displays a competitive responsivity of 4.5 A W −1 under 10.0 µm illumination at room temperature, which profit from the strong light absorption in the MIR region …”

“…Such outstanding performance might be attributed to the high crystal quality and superior field effect transistor properties of a competitive mobility of 7.6 cm 2 V −1 s −1 and an ultrahigh on/off ratio exceeding 10 8 , which minimize the defect density, the deleterious effects of defects and trap states, and facilitate photogenerated carriers transport in the HfS 2 channel . More recently, the 2D noble metal dichalcogenides PtSe 2 is also emerging in IR photodetection . Both the monolayer and bilayer PtSe 2 are indirect bandgaps of ≈1.2 and ≈0.3 eV, respectively.…”

“…Inset shows the crystal structure of PtSe 2 . Reproduced under the terms and conditions of the Creative Commons Attribution License 4.0 . Copyright 2018, The Authors, published by Springer Nature.…”

Multimechanism Synergistic Photodetectors with Ultrabroad Spectrum Response from 375 nm to 10 µm

“…[16][17][18] Devices based on MoS 2 , a typical member of the TMDs family, exhibit ultrasensitive and ultrahigh gain characteristics for photodetector applications. [17,[20][21][22][23] Limited by absorption efficiency, these infrared detectors typically have low photocurrent gain and low quantum efficiency. 2D semiconductors with narrow bandgaps, such as platinum diselenide (PtSe 2 ), black phosphorene, and black arsenic phosphorus, were recently discovered and used to fabricate the infrared detectors.…”