Construction of Bi₂O₂Se/Bi₂Se₃ Van Der Waals Heterostructures for Self-Powered and Broadband Photodetectors

Abstract

Due to its superior carrier mobility and high air stability, the emerging two-dimensional (2D) layered bismuth oxyselenide (Bi 2 O 2 Se) nanosheets have attracted extensive attention, showing great potential for applications in the electronic and optoelectronic fields. However, a high mobility easily leads to a high dark current, seriously restricting optoelectronic applications, especially in the field of photodetectors. In this paper, we report a high-quality Van der Waals (vdWs) Bi 2 O 2 Se/Bi 2 Se 3 heterostructure on a fluorophlogopite substrate, exhibiting excellent photodiode characteristics. By means of the effective separation of photogenerated electrons and holes by a junction barrier at the interface, the current on/off ratio is up to about 3 × 10 3 under 532 nm laser illumination with zero bias. In addition, the photodetector not only achieves a fast response speed of 41 ms but also has a broadband photoresponse from 532 to 1450 nm (visible−NIR). Additionally, the responsivity can reach 0.29 A/W, and the external quantum efficiency exceeds 69% when the device operates in the reverse bias condition. The results indicate that the Bi 2 O 2 Se/Bi 2 Se 3 vdWs heterostructure has great potential for self-powered, broadband, and fast photodetection applications.

Fast Fabrication of WS2/Bi2Se3 Heterostructures for High-Performance Photodetection

“…The tunneling current cannot be significantly higher than the thermionic current, which results in a stably low bias current of ≈ 6 × 10 –12 A at −4 V condition. On the opposite, the energy band of WS 2 is elevated under a forward bias voltage as shown in Figure d, which allows the electrons to transfer freely from WS 2 to Bi 2 Se 3 , resulting in a relatively high current . Because of the unavoidable surface oxidation of Bi 2 Se 3 , there exists a barrier between the interface, leading the “open” voltage to become slightly shifted.…”

“…Then, 2D Bi 2 Se 3 flakes were grown on fluorophlogopite mica substrate by low-pressure physical vapor deposition . The Bi 2 Se 3 powder was placed in the center of the furnace equipped with a quartz tube, and the fluorophlogopite mica substrates were placed downstream 8–11 cm away from the center.…”

Self-Powered and Broadband Bismuth Oxyselenide/p-Silicon Heterojunction Photodetectors with Low Dark Current and Fast Response

“…Therefore, it is crucial for device integration to suppress the dark current and decrease the power consumption of Bi 2 O 2 Se-based photodetectors. Designed Bi 2 O 2 Se-based heterojunctions, such as Bi 2 O 2 Se/graphene, Bi 2 O 2 Se/Bi 2 Te 2 Se, Bi 2 O 2 Se/WS 2 , Bi 2 O 2 Se/WSe 2 , and Bi 2 O 2 Se/Bi 2 Se 3 , can address this bottleneck by lowering the dark current and satisfying the specifications of self-powered photodetection, yet it is still challenging for their applications due to the difficulty of large-scale synthesis. Studies have shown that the synthesis of Bi 2 O 2 Se using Bi 2 O 3 and Se as co-evaporation sources , can greatly reduce the residual carrier concentration while ensuring high carrier mobility, which contributes to a very low threshold voltage and low power consumption.…”

Bi2O2Se-based integrated multifunctional optoelectronics

“… 60 The heterostructure of Bi 2 O 2 Se/graphene was reported for the demonstration of photodetector and short channel FET (50 nm) by Tan et al 61 In another study by Yang et al , Bi 2 O 2 Se/graphene hybrid structure was utilized to demonstrate multifunctional optoelectronics, including photodetector, optical synapse, and logic gate by the control of optical wavelengths. 62 Some recent reports focused on Bi 2 O 2 Se-based heterostructures: Bi 2 O 2 Se/Bi 2 Se 3 , 63 Bi 2 Te 2 Se/Bi 2 O 2 Se, 64 Bi 2 O 2 Se/TMDs, 65 and Bi 2 O 2 Se/CsPbBr 3 , 66 showing potential use of Bi 2 O 2 Se in combination with other materials for optoelectronic applications. Although Bi 2 O 2 Se shows competent light sensing property in a wide band, multifunctional optoelectronic by only the Bi 2 O 2 Se based structure has not been explored so far.…”