Rhenium Diselenide (ReSe₂) Near‐Infrared Photodetector: Performance Enhancement by Selective p‐Doping Technique

Abstract

In this study, a near‐infrared photodetector featuring a high photoresponsivity and a short photoresponse time is demonstrated, which is fabricated on rhenium diselenide (ReSe2) with a relatively narrow bandgap (0.9–1.0 eV) compared to conventional transition‐metal dichalcogenides (TMDs). The excellent photo and temporal responses, which generally show a trade‐off relation, are achieved simultaneously by applying a p‐doping technique based on hydrochloric acid (HCl) to a selected ReSe2 region. Because the p‐doping of ReSe2 originates from the charge transfer from un‐ionized Cl molecules in the HCl to the ReSe2 surface, by adjusting the concentration of the HCl solution from 0.1 to 10 m, the doping concentration of the ReSe2 is controlled between 3.64 × 1010 and 3.61 × 1011 cm−2. Especially, the application of the selective HCl doping technique to the ReSe2 photodetector increases the photoresponsivity from 79.99 to 1.93 × 103 A W−1, and it also enhances the rise and decay times from 10.5 to 1.4 ms and from 291 to 3.1 ms, respectively, compared with the undoped ReSe2 device. The proposed selective p‐doping technique and its fundamental analysis will provide a scientific foundation for implementing high‐performance TMD‐based electronic and optoelectronic devices.

Enhancement of Photodetective Properties on Multilayered MoS2 Thin Film Transistors via Self-Assembled Poly-L-Lysine Treatment and Their Potential Application in Optical Sensors

“…Figure 8 e presents 2~6 times higher responsivities and 1.3~3.5 times enlarged detectivities of the PLL-treated m-MoS 2 TFTs, compared to the bare m-MoS 2 TFTs. These behaviors are well matched with previous results [ 43 , 44 , 45 , 47 ]. As a result, Figure 8 validates the improved photoresponse of the m-MoS 2 TFTs after PLL treatment, which is possibly due to the increased number of tightly bound trions and their lifetime as shown in Figure 7 a [ 46 , 57 ].…”

“…In addition to revealing the high optoelectrical performance of m-MoS 2 TFTs by comparison with a-Si:H TFTs, the photoresponsivity can be enhanced by molecular doping treatment [ 43 , 44 , 45 ]. Although there are different techniques to improve the photodetector’s performance, the molecular doping method has several advantages, as it does not need a change in the device’s structure or the addition of different channel materials or layers but consist of a low temperature process, ultra-thin thickness, and post-process compatibility after device fabrication.…”

Efficient ReSe2 Photodetectors with CVD Single-Crystal Graphene Contacts

“…The calculated responsivity with maximum illumination power (P 530nm = 2.8 × 10 −3 W.cm −2 and P 790nm = 2.0 × 10 −3 W.cm −2 ) is R 530nm = 4.7 × 10 2 A/W and R 790nm = 3.3 × 10 2 A/W are superior to the second device we fabricated with Au contacts (flake thickness of 58 nm and S = 26 μm 2 ) and to other works on exfoliated ReSe 2 devices. Furthermore, these values are similar to those obtained for a p-doped ReSe 2 device fabricated [ 62 ] (see Table 2 ). The secondary photocurrent measure depends on the majority carrier concentration or on the photocarrier with the higher mobility, μ.…”

Synthesis of two‐dimensional transition metal dichalcogenides for electronics and optoelectronics

“…2D‐layered TMDCs and their vdWHs materials have been attracted enormous research interest because of their outstanding response to the light, which promotes the potential applications in next‐generation optoelectronic devices, including photodetectors, 188‐192 photovoltaics, 193 light emitting diodes (LEDs), 194,195 and so on. Herein, we mainly summarize the recent progress of optoelectronic applications in the following three aspects: photodetectors, photovoltaics, and LEDs.…”