Improved Photoelectrical Properties of MoS₂ Films after Laser Micromachining

Abstract

Direct patterning of ultrathin MoS2 films with well-defined structures and controllable thickness is appealing since the properties of MoS2 sheets are sensitive to the number of layer and surface properties. In this work, we employed a facile, effective, and well-controlled technique to achieve micropatterning of MoS2 films with a focused laser beam. We demonstrated that a direct focused laser beam irradiation was able to achieve localized modification and thinning of as-synthesized MoS2 films. With a scanning laser beam, microdomains with well-defined structures and controllable thickness were created on the same film. We found that laser modification altered the photoelectrical property of the MoS2 films, and subsequently, photodetectors with improved performance have been fabricated and demonstrated using laser modified films.

Ultrahigh, Ultrafast, and Self‐Powered Visible‐Near‐Infrared Optical Position‐Sensitive Detector Based on a CVD‐Prepared Vertically Standing Few‐Layer MoS2/Si Heterojunction

“…In addition, the lateral photovoltage balance values remain nearly constant for each laser power without depending on the chopper frequency, and V max increases gradually until becoming saturated with increasing laser power, as shown in Figure 4f, which is consistent with the LPE results. More importantly, it is noteworthy that the response time of this heterojunction is much faster than those of most reported MoS 2 ‐based photodetectors 10, 11, 12, 30, 59, 60, 61, 62, 63. Though ultrafast and stable photoresponse with no degradation, as well as resistance capacitance (RC)‐limited bandwidth, of the optoelectric devices is one of the basic requirements for applications in high‐speed optical communications, until now, the frequency of the modulated laser has been lower than 4000 Hz in most of the previously reported nano‐PDs, which will hinder their application in dynamic real‐time detection of the optical signal.…”

Bifunctional Sensing Characteristics of Chemical Vapor Deposition Synthesized Atomic-Layered MoS2

“…37,38 The photoresponsivity, a critical factor in evaluating photodetector performance, ranged from 28 to 71 mA/W under different wavelength light sources (Figure 3d), comparable to recently reported values. 39 The photosensing performance would be further increased by optimizing contact metal or device architecture. We also evaluated the transient photoresponse characteristics under voltage or intensity variation.…”

Manipulation of local optical properties and structures in molybdenum-disulfide monolayers using electric field-assisted near-field techniques

“…However, its very low light intensity, typically in the order of 10 nW μm −2 , presents a major technical challenge, and accordingly hardly any one has expected near-field light can be applied to etching of TMDCs. Laser thinning and patterning of MoS 2 have been reported252829. However, a laser power of several 10 μW μm −2 is required for them, which is by an order of 3 higher than the maximum available intensity of near-field light, several 10 nW μm −2 .…”