Band Alignment and High-Performance Unbiased Vis–NIR Photodetection of Semimetal Bi 4 Se 3 /Si Heterostructures

作者：Junye Li, Peng Zhao, Zetian Mi, Yiwen Dai, Yingchao Liu, Haining Ji, Handong Li, Xiaobin Niu, Zhiming M. Wang · 发表于：Nano Letters · 年份：2025 · DOI：10.1021/acs.nanolett.5c03759 · 被引用次数：2 · 研究领域：Topological Materials and Phenomena、Advanced Thermoelectric Materials and Devices、Semiconductor materials and interfaces

Semimetals have recently attracted much research interest in electronics as contact layers due to their appealing physical properties, such as a layered structure and a low density of states at the Fermi level. Herein, we study the band alignment and unbiased visible-to-near-infrared (Vis–NIR) photodetection of semimetal Bi 4 Se 3 /Si heterostructures. High-quality Bi 4 Se 3 /Si heterostructures are prepared by epitaxially growing (001)-orientated Bi 4 Se 3 films on H-passivated Si(111) substrates. Ohmic and Schottky contact properties of Bi 4 Se 3 to n - and p -Si are revealed. Analysis of the temperature dependence of reverse thermionic emission suggests that the height of the Schottky barrier at the Bi 4 Se 3 / p -Si junction is 0.37 eV, thus depicting its band alignment. A photodiode consisting of the Bi 4 Se 3 / p -Si heterostructure exhibits fast unbiased broadband detection in Vis–NIR regions (405–1064 nm) with ultralow dark current (0.5 nA), good responsivity (288 mA W −1 ) and decent detectivity (3.28 × 10 8 Jones) at 980 nm, and excellent stability.