Liquid‐Exfoliated 2D Materials for Optoelectronic Applications

Abstract

Two‐dimensional (2D) materials have attracted tremendous research attention in recent days due to their extraordinary and unique properties upon exfoliation from the bulk form, which are useful for many applications such as electronics, optoelectronics, catalysis, etc. Liquid exfoliation method of 2D materials offers a facile and low‐cost route to produce large quantities of mono‐ and few‐layer 2D nanosheets in a commercially viable way. Optoelectronic devices such as photodetectors fabricated from percolating networks of liquid‐exfoliated 2D materials offer advantages compared to conventional devices, including low cost, less complicated process, and higher flexibility, making them more suitable for the next generation wearable devices. This review summarizes the recent progress on metal–semiconductor–metal (MSM) photodetectors fabricated from percolating network of 2D nanosheets obtained from liquid exfoliation methods. In addition, hybrids and mixtures with other photosensitive materials, such as quantum dots, nanowires, nanorods, etc. are also discussed. First, the various methods of liquid exfoliation of 2D materials, size selection methods, and photodetection mechanisms that are responsible for light detection in networks of 2D nanosheets are briefly reviewed. At the end, some potential strategies to further improve the performance the devices are proposed.

Perspectives of 2D Materials for Optoelectronic Integration

“…Nowadays, there are generally two major methods of synthesizing and preparing 2D materials for optoelectronic devices, i.e., top‐down methods and bottom‐up methods. More specifically, top‐down methods mainly include micromechanical exfoliation and liquid phase exfoliation methods, [ 15,33–42 ] while bottom‐up methods generally include chemical vapor deposition (CVD) and hydrothermal/solvothermal methods. [ 43–53 ]…”

“…Liquid phase exfoliation can be generally divided into “chemical exfoliation” and “direct liquid exfoliation” based on whether chemical reactions play a major role. [ 35 ] Direct exfoliation methods can retain the original physical and electronic properties of the 2D materials. Generally, liquid phase exfoliation has low cost and relatively high yield in comparison with micromechanical exfoliation.…”

“…Nowadays, there are generally two major methods of synthesizing and preparing 2D materials for optoelectronic devices, i.e., top-down methods and bottom-up methods. More specifically, top-down methods mainly include micromechanical exfoliation and liquid phase exfoliation methods, [15,[33][34][35][36][37][38][39][40][41][42] while bottom-up methods generally include chemical vapor deposition (CVD) and hydrothermal/solvothermal methods. [43][44][45][46][47][48][49][50][51][52][53] In earlier studies of 2D material, the preparation of 2D nanosheets for fundamental property investigation and functional device fabrication is highly relied on the micromechanical exfoliation.…”

Flexible Self‐Powered Electrochemical Photodetector Functionalized by Multilayered Tantalum Diselenide Nanocrystals

“…[26] Liquid exfoliated 2D materials such as graphene, BP, antimonene, graphitic carbon nitride (g-C 3 N 4 ), transition metal dichalcogenides (TMDCs), layered III-VI semiconductors, topological insulators, and MXenes bring for the next generation of high-performance wearable optoelectronic and sensing devices. [27] Photodetectors are the most important sensors with a wide range of applications in communication and sensing. However, most of the photodetectors are designed in such a way that their operation requires an external power source for high performance which hinder their applications in wireless monitoring and sensing.…”

“…[ 26 ] Liquid exfoliated 2D materials such as graphene, BP, antimonene, graphitic carbon nitride (g‐C 3 N 4 ), transition metal dichalcogenides (TMDCs), layered III–VI semiconductors, topological insulators, and MXenes bring for the next generation of high‐performance wearable optoelectronic and sensing devices. [ 27 ]…”