Giant Superlinear Power Dependence of Photocurrent Based on Layered Ta2 NiS5 Photodetector

Xianghao Meng; Yuhan Du; Wenbin Wu; Nesta Benno Joseph; Xing Deng; Jinjin Wang; Jianwen Ma; Zeping Shi; Binglin Liu; Yuanji Ma; Fangyu Yue; Ni Zhong; Ping-Hua Xiang; Cheng Zhang; Chun-Gang Duan; Awadhesh Narayan; Zhenrong Sun; Junhao Chu; Xiang Yuan

doi:10.1002/advs.202300413

Giant Superlinear Power Dependence of Photocurrent Based on Layered Ta₂ NiS₅ Photodetector

Adv Sci (Weinh). 2023 Jul;10(20):e2300413. doi: 10.1002/advs.202300413. Epub 2023 Apr 28.

Authors

Xianghao Meng^{1

2}, Yuhan Du^{1

2}, Wenbin Wu^{1

2}, Nesta Benno Joseph³, Xing Deng⁴, Jinjin Wang⁴, Jianwen Ma⁵, Zeping Shi^{1

2}, Binglin Liu^{1

2}, Yuanji Ma^{1

2}, Fangyu Yue^{1

2

4}, Ni Zhong^{1

2

4}, Ping-Hua Xiang^{1

2

4}, Cheng Zhang^{5

6}, Chun-Gang Duan^{1

2

4}, Awadhesh Narayan³, Zhenrong Sun^{1

2}, Junhao Chu^{2

4

7}, Xiang Yuan^{1

2}

Affiliations

¹ State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China.
² School of Physics and Electronic Science, East China Normal University, Shanghai, 200241, China.
³ Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, 560012, India.
⁴ Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University, Shanghai, 200241, China.
⁵ State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai, 200433, China.
⁶ Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai, 201210, China.
⁷ Institute of Optoelectronics, Fudan University, Shanghai, 200438, China.

Abstract

Photodetector based on two-dimensional (2D) materials is an ongoing quest in optoelectronics. 2D photodetectors are generally efficient at low illuminating power but suffer severe recombination processes at high power, which results in the sublinear power-dependent photoresponse and lower optoelectronic efficiency. The desirable superlinear photocurrent is mostly achieved by sophisticated 2D heterostructures or device arrays, while 2D materials rarely show intrinsic superlinear photoresponse. This work reports the giant superlinear power dependence of photocurrent based on multilayer Ta₂ NiS₅ . While the fabricated photodetector exhibits good sensitivity (3.1 mS W^-1 per □) and fast photoresponse (31 µs), the bias-, polarization-, and spatial-resolved measurements point to an intrinsic photoconductive mechanism. By increasing the incident power density from 1.5 to 200 µW µm^-2 , the photocurrent power dependence varies from sublinear to superlinear. At higher illuminating conditions, prominent superlinearity is observed with a giant power exponent of γ = 1.5. The unusual photoresponse can be explained by a two-recombination-center model where density of states of the recombination centers (RC) effectively closes all recombination channels. The photodetector is integrated into camera for taking photos with enhanced contrast due to superlinearity. This work provides an effective route to enable higher optoelectronic efficiency at extreme conditions.

Keywords: high-power sensor; layered ternary chalcogenides; photoconductive detector; superlinear photoresponse.

Abstract

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