Broadband Photodetectors Based on Graphene–Bi₂Te₃ Heterostructure

Abstract

Recently, research on graphene based photodetectors has drawn substantial attention due to ultrafast and broadband photoresponse of graphene. However, they usually have low responsivity and low photoconductive gain induced by the gapless nature of graphene, which greatly limit their applications. The synergetic integration of graphene with other two-dimensional (2D) materials to form van der Waals heterostructure is a very promising approach to overcome these shortcomings. Here we report the growth of graphene-Bi2Te3 heterostructure where Bi2Te3 is a small bandgap material from topological insulator family with a similar hexagonal symmetry to graphene. Because of the effective photocarrier generation and transfer at the interface between graphene and Bi2Te3, the device photocurrent can be effectively enhanced without sacrificing the detecting spectral width. Our results show that the graphene-Bi2Te3 photodetector has much higher photoresponsivity (35 AW(-1) at a wavelength of 532 nm) and higher sensitivity (photoconductive gain up to 83), as compared to the pure monolayer graphene-based devices. More interestingly, the detection wavelength range of our device is further expanded to near-infrared (980 nm) and telecommunication band (1550 nm), which is not observed on the devices based on heterostructures of graphene and transition metal dichalcogenides.

Booming Development of Group IV–VI Semiconductors: Fresh Blood of 2D Family

“…Moreover, in‐situ growth of vertical ( Figure 11 a) and lateral (Figure 11b) heterostructures are very important for exploring the novel physical properties, considering that most of the reports on 2D GIVMCs is currently based on the transferred heterojunctions,130, 243, 244 which may harm the electronic properties231, 240 due to the dangling bonds and adsorbates at the interface. In addition, graphene is an ideal template to promote the nucleation and growth of other 2DLMCs crystals for producing functional hybrid structures via CVD method (Figure 11c),198, 204, 207 which may result in the modulation of the electric and optical properties coupled with graphene. The fast growing field calls for more works to fully understand the junction formation and resulted physical properties in 2D GIVMCs crystals.…”

“…Van der Waals (vdW) heterostructures composed of 2D layered materials have been attempted intensively recently due to the novel physical properties covering a wide range of electronic, optical, and optoelectronic systems 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242. Jo and co‐workers130 synthesized polymorphic 2D tin‐sulfides of either p‐type SnS or n‐type SnS 2 via adjusting hydrogen during the process.…”

Photogating in Low Dimensional Photodetectors

“…To achieve a high performance, graphene is preferred to be used as the channel of a hybrid structure due to its high mobility 32, 39, 88, 89, 90, 91. In the year of 2013, Roy et al incorporated graphene with MoS 2 wherein graphene acts as the channel and MoS 2 acts as the gating layer, as shown in Figure 9 a 32.…”

Highly efficient plasmon excitation in graphene-Bi_2Te_3 heterostructure

“…Thus, the lattice mismatch between Bi 2 Te 3 and graphene is 2.7% (0.12 Å), which is ideal for van der Waals epitaxial growth [ Fig. 1(b)] [14][15][16][17]. This work utilizes the chemical vapor deposition (CVD) method to fabricate the graphene-Bi 2 Te 3 plasmonic heterostructure.…”