Ultrafast Charge Transfer 2D MoS2 /Organic Heterojunction for Sensitive Photodetector

Zhuhua Xu; Miao He; Qinke Wu; Chengcheng Wu; Xubiao Li; Bilu Liu; Man-Chung Tang; Jie Yao; Guodan Wei

doi:10.1002/advs.202207743

Ultrafast Charge Transfer 2D MoS₂ /Organic Heterojunction for Sensitive Photodetector

Adv Sci (Weinh). 2023 Apr;10(12):e2207743. doi: 10.1002/advs.202207743. Epub 2023 Feb 19.

Authors

Zhuhua Xu^{1

2}, Miao He^{1

2}, Qinke Wu^{1

2}, Chengcheng Wu^{1

2}, Xubiao Li^{1

2}, Bilu Liu^{1

2

3}, Man-Chung Tang², Jie Yao⁴, Guodan Wei^{1

2}

Affiliations

¹ Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University, Shenzhen, 518055, China.
² Institute of Materials Research, Tsinghua Shenzhen International Graduate School (SIGS), Tsinghua University, Shenzhen, 518055, China.
³ Shenzhen Geim Graphene Center, Tsinghua Shenzhen International Graduate School (SIGS), Tsinghua University, Shenzhen, 518055, China.
⁴ Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA.

Abstract

The 2D MoS₂ with superior optoelectronic properties such as high charge mobility and broadband photoresponse has attracted broad research interests in photodetectors (PD). However, due to the atomic thin layer of 2D MoS₂ , its pure photodetectors usually suffer from inevitable drawbacks such as large dark current, and intrinsically slow response time. Herein, a new organic material BTP-4F with high mobility is successfully stacked with 2D MoS₂ film to form an integrated 2D MoS₂ /organic P-N heterojunction, facilitating efficient charge transfer as well as significantly suppressed dark current. As a result, the as-obtained 2D MoS₂ /organic (PD) has exhibited excellent response and fast response time of 332/274 µs. The analysis validated photogenerated electron transition from this monolayer MoS₂ to subsequent BTP-4F film, whereas the transited electron is originated from the A^- exciton of 2D MoS₂ by temperature-dependent photoluminescent analysis. The ultrafast charge transfer time of ≈0.24 ps measured by time-resolved transient absorption spectrum is beneficial for efficient electron-hole pair separation, greatly contributing to the obtained fast photoresponse time of 332/274 µs. This work can open a promising window to acquire low-cost and high-speed (PD).

Keywords: P-N heterojunction; charge transfer; monolayer MoS2; organic thin film; photodetector.

Abstract

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