Large-Area Ultraviolet Photodetectors Based on p-Type Multilayer MoS2 Enabled by Plasma Doping

Xiao-Mei Zhang,Ming-Yen Lu,Sian-Hong Tseng

doi:10.3390/app9061110

Xiao-Mei Zhang, Ming-Yen Lu + Show 1 more

Open Access

https://doi.org/10.3390/app9061110

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Abstract

Two-dimensional (2D) MoS2 has recently become of interest for applications in broad range photodetection due to their tunable bandgap. In order to develop 2D MoS2 photodetectors with ultrafast response and high responsivity, up-scalable techniques for realizing controlled p-type doping in MoS2 is necessary. In this paper, we demonstrate a p-type multilayer MoS2 photodetector with selective-area doping using CHF3 plasma treatment. Microscopic and spectroscopic characterization techniques, including atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), are used to investigate the morphological and electrical modification of the p-type doped MoS2 surface after CHF3 plasma treatment. Back-gated p-type MoS2 field-effect transistors (FETs) are fabricated with an on/off current ratio in the order of 103 and a field-effect mobility of 65.2 cm2V−1s−1. They exhibit gate-modulated ultraviolet photodetection with a rapid response time of 37 ms. This study provides a promising approach for the development of mild plasma-doped MoS2 as a 2D material in post-silicon electronic and optoelectronic device applications.

Highlights

Two-dimensional (2D) transition metal dichalcogenides (TMDCs), such as MoS2, have attracted considerable attention owing to the unique optical and electronic properties related to its 2D ultrathin atomic layer structure [1]
2D TMDC photodetectors fabricated with transferred van der Waals heterostructures or chemical vapor deposition-grown hybrids are typically characterized with low responsivity
In the case of multilayer MoS2, which is exposed to energetic F-plasma treatment, p-type doping of the exposed area has been shown

Summary

Introduction

Two-dimensional (2D) transition metal dichalcogenides (TMDCs), such as MoS2 , have attracted considerable attention owing to the unique optical and electronic properties related to its 2D ultrathin atomic layer structure [1]. 2D TMDC photodetectors fabricated with transferred van der Waals heterostructures or chemical vapor deposition-grown hybrids are typically characterized with low responsivity. This is due to the lack of a photo-gain mechanism or by resilient photoconductivity in the heterojunction structure [8]. In the case of multilayer MoS2 , which is exposed to energetic F-plasma treatment, p-type doping of the exposed area has been shown. This work suggests the potential application of the mild plasma-doped p-type multilayer MoS2 in UV photodetectors for environmental monitoring, human health monitoring, and biological analysis

Experimental Section

Results and Discussion

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Conclusions