Seed‐Induced Vertical Growth of 2D Bi₂O₂Se Nanoplates by Chemical Vapor Transport

Abstract

As two‐dimensional (2D) layered materials attract more attention owing to their unique optical, electrical, and thermal properties, there are persistent efforts to grow high‐quality 2D layered materials for fundamental research and device applications. While large‐area 2D layered materials with high crystal quality can be obtained through chemical vapor transport, the strong binding between 2D layered materials and substrates poses a significant challenge for attempts to reveal their intrinsic properties and to use these 2D building blocks for constructing advanced heterostructured devices. Therefore, it would be ideal to grow high‐quality 2D materials with minimized contact and binding with substrate. Through both calculation and experiment, it is demonstrated that by introducing a seed layer at the nucleation stage, the crystallographic disregistry and the corresponding adhesion energy between 2D materials and substrate can be altered, resulting in a change of crystal surface in contact with the substrate, and therefore vertical growth of 2D materials on substrates. As an example, it is demonstrated that with Bi2O3 serving as a seed layer, vertical growth of 2D plates of Bi2O2Se on mica substrates can be realized. These vertically grown 2D nanoplates of Bi2O2Se can be conveniently transferred with their thermal properties investigated for the first time.

Self‐Driven WSe2/Bi2O2Se Van der Waals Heterostructure Photodetectors with High Light On/Off Ratio and Fast Response

“…has gained wide interest due to its excellent electron mobility and good ambient stability. [ 16,17 ] Tremendous progress has been achieved in the structural analysis, [ 17–19 ] controlled synthesis, [ 20–23 ] precision etching, [ 24 ] noncorrosive transfer, [ 23,25 ] and large area growth [ 26,27 ] of 2D Bi 2 O 2 Se, which paved the way for advanced electronics and optoelectronics device applications. [ 28–31 ] The 2D Bi 2 O 2 Se exhibits an ultra‐high mobility (≈20 000 cm 2 V −1 s −1 ) comparable to graphene and proper band gap of 0.8 eV, it is thus worth exploring its merits in high‐performance photodetection applications.…”

Van der Waals Epitaxy of Bi2Te2Se/Bi2O2Se Vertical Heterojunction for High Performance Photodetector

“…[ 6–14 ] Extensive efforts have been paid to tailor the intrinsic material properties in Bi 2 O 2 Se based devices such as transistors, memristors, and photodetectors by optimizing material synthesis. [ 15–19 ] For example, Bi 2 O 2 Se based phototransistor has been achieved by He et al. with responsivity reaching 6.5 A W –1 and detectivity up to 8.3 × 10 11 Jones in the visible range.…”

Inclined Ultrathin Bi2O2Se Films: A Building Block for Functional van der Waals Heterostructures

“…the long edge of the rectangular-shaped inclined Bi 2 O 2 Se films or to one edge of the square-shaped in-plane Bi 2 O 2 Se. From the bright field (BF) STEM image in Figure2a, the inclined angle between Bi 2 O 2 Se and the mica surface is 56°, and there are no buffer layers at the interface, which is different from vertical Bi 2 O 2 Se or Bi 2 Te 3 films grown on mica substrates, where interfacial Bi 2 O 3 layers exist 23,30. Additionally, lattice plane indices are marked in Figure2a, and notably, it is the (012) crystal plane from inclined Bi 2 O 2 Se that forms the interface upon mica.…”