Toward High‐Performance Photodetectors Based on 2D Materials: Strategy on Methods

Abstract

Graphene and graphene‐like 2D layered materials such as black phosphorus, transition‐metal dichalcogenides, oxides, chalcogenides, and so forth have attracted tremendous attention due to their unique crystal structures, mechanical, and physical properties, as well as their variable bandgaps that range from 0 to 6 eV, which have offered their utilization in versatile devices. Using these materials as the active channel, many novel electrical and optoelectronic devices have been reported. Among the various important devices applications, photodetectors based on 2D materials have been extensively investigated with varied performance due to the different species and detection mechanisms. Here, the methods to improve the performance of 2D‐material‐based photodetectors are reviewed. There are five kinds of strategies regarding methods, including surface plasmon enhancement, charge‐transfer assistance, optical‐waveguide integration, graphene sandwiched structures, and heterostructures directly grown by CVD, which are developed and widely reported in recent years. For each method, the device design, performance, and mechanism are introduced and discussed systematically. Finally, a summary is provided to afford the principle to further enhance the performance of photodetectors based on 2D materials, with a perspective for their practical applications in the future.

2D In2S3 Nanoflake Coupled with Graphene toward High‐Sensitivity and Fast‐Response Bulk‐Silicon Schottky Photodetector

“…Driven by the increased built‐in electric field, the photogenerated electrons from bulk Si were quickly flowed into the graphene and extracted by the electrode, creating photocurrent ( I ph1 ) pointing from graphene to Si. Compared to the original graphene/Si device, the introduction of In 2 S 3 nanoflake results in faster separation of photoexcited carriers, making them to be extracted by the electrodes quickly, which speeding up the response rate . At the same time, the photoexcited holes from In 2 S 3 were rapidly injected into the graphene layer and then transferred to bulk Si, meanwhile leaving the photogenerated electrons in the In 2 S 3 nanoflake.…”

Flexible Photodetector Based on 2D Materials: Processing, Architectures, and Applications

“…In comparison with the state of art rigid photodetector, the strategies and processing methods to produce high optoelectronic key performance metrics are still underdeveloped . Hybrid graphene photodetectors have achieved responsivities of 10 7 A W −1 and detectivity of 10 7 , while still maintaining a response time from 0.1 to 1 ms .…”

“…In comparison with the state of art rigid photodetector, the strategies and processing methods to produce high optoelectronic key performance metrics are still underdeveloped. [1,124,125] Hybrid graphene photodetectors have achieved responsivities of 10 7 A W −1 and detectivity of 10 7 , while still maintaining a response time from 0.1 to 1 ms. [126] TMDs have also reached a value of 1.8 × 10 5 A W −1 and detectivity higher than 10 14 for WSe 2 [127] and similarly to graphene, they have also been combined with other semiconductors to enhance even further their responsivity 6 × 10 5 A W −1 and detectivity 7 × 10 14 . [128] Other chalcogenides such as InSe [129] and GaTe [130] have achieved responsivities higher than 10 4 A W −1 and detectivity of 10 13 while maintaining a response speed under 1 s. 2D material heterostructures architectures are also highly developed including architecture with more than two 2D material which reaches up to responsivities of 1 × 10 14 A W −1 and detectivity of 1 × 10 15 with an ultrafast rise time of 53.6 us.…”

Novel two-dimensional monoelemental and ternary materials: growth, physics and application

“…Their bandgap is in the range of 0.2-2.1 eV, with broadband optical absorption efficient (>10 4 cm −1 ) and moderate carrier mobility (10-10 2 cm 2 · V −1 · s −1 ). Moreover, crystal type, bandgap structure, unique physics, (opto)electronic devices performance and biomedical application have been discussed by a number of reviews and research papers in recent years [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]. Nevertheless, because of the covalent bonding between the anion/ion atoms and the general weak interlayer coupling effect, TMCs and their heterostructures have suffered from intrinsic/extrinsic disorder (vacancies, anti-site, substitution) and interface impurity (small molecules), leading to the downtrend or strange phenomenon in electronic and optoelectronic properties [38,39].…”