Charge Transfer Properties of Heterostructures Formed by Bi₂O₂Se and Transition Metal Dichalcogenide Monolayers

Abstract

Atomically thin bismuth oxyselenide (Bi2O2Se) exhibits attractive properties for electronic and optoelectronic applications, such as high charge‐carrier mobility and good air stability. Recently, the development of Bi2O2Se‐based heterostructures have attracted enormous interests with promising prospects for diverse device applications. Although the electrical properties of Bi2O2Se‐based heterostructures have been widely studied, the interlayer charge transfer in these heterostructures remains elusive, despite its importance in harnessing their emergent functionalities. Here, a comprehensive experimental investigation on the interlayer charge transfer properties of two heterostructures formed by Bi2O2Se and representative transition metal dichalcogenides (namely, WS2/Bi2O2Se and MoS2/Bi2O2Se) is reported. Kelvin probe force microscopy is used to measure the work functions of the samples, which are further employed to establish type‐II band alignment of both heterostructures. Photoluminescence quenching is observed in each heterostructure, suggesting high charge transfer efficiency. Time‐resolved and layer‐selective pump–probe measurements further prove the ultrafast interlayer charge transfer processes and formation of long‐lived interlayer excitons. These results establish the feasibility of integrating 2D Bi2O2Se with other 2D semiconductors to fabricate heterostructures with novel charge transfer properties and provide insight for understanding the performance of optoelectronic devices based on such 2D heterostructures.

Bi2O2Te Nanosheets Saturable Absorber‐Based Passive Mode‐Locked Fiber Laser: From Soliton Molecules to Harmonic Soliton

“…[10] The unique structure endows it with outstanding characteristics that cannot be provided by other 2D materials, in addition to further optoelectronic advantages; thus, resulting in a wide range of applications. [11,12] Thus, it is necessary to identify potential 2D bismuth oxychalcogenide nanomaterials and to investigate their characteristics as well as potential applications. Bismuth oxyselenide (Bi 2 O 2 Se) is the first synthesized Bi 2 O 2 X material by gas-phase transport reaction.…”

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

“…To comprehend the carrier transport behavior of the device, the electronic band alignment of the WS 2 /Bi 2 Se 3 heterostructure is established as shown in Figure b. According to the previously reported measurement results and our PL spectrum, the conduction band minimum ( E c ), valence band maximum ( E v ), and Fermi level ( E f ) of the WS 2 (Bi 2 Se 3 ) are located at ∼−3.87 eV (−4.91 eV), −5.88 eV (−5.21 eV), and −4.81 eV (−4.61 eV), respectively. , From the electronic band before contact, the Fermi level of Bi 2 Se 3 is higher than that of WS 2 . To prove the band difference, Kelvin probe force microscopy (KPFM) is performed to measure the surface potential of the heterostructure, as shown in Figure S6.…”

“…The in-plane and out-of-plane vibration modes for the individual and overlap regions of WS 2 at 355 and 420 cm –1 , respectively, are also shown in Figure e. The ratio of the intensities of the A 1g and E 2g 1 peaks is less than 0.5, which also indicates its monolayer thickness . The WS 2 and Bi 2 Se 3 characteristic peaks show no shift in the heterostructure, demonstrating that the lattice properties of WS 2 and Bi 2 Se 3 are not changed after half-wet transfer and thermal annealing.…”

“…The ratio of the intensities of the A 1g and E 2g 1 peaks is less than 0.5, which also indicates its monolayer thickness. 42 The WS 2 and Bi 2 Se 3 characteristic peaks show no shift in the heterostructure, demonstrating that the lattice properties of WS 2 and Bi 2 Se 3 are not changed after half-wet transfer and thermal annealing. 42,43 From the electronic band before contact, the Fermi level of Bi 2 Se 3 is higher than that of WS 2 .…”

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.…”