Controlled Epitaxial Growth of (hk1)‐Sb2Se3 Film on Cu9S5 Single Crystal via Post‐Annealing Treatment for Photodetection Application

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2024-05, Vol.20 (22), p.e2308229-n/a
• Main Authors: Xiao, Liu, Liu, Zhiying, Zhang, Gang, Feng, Wenlin
• Format: Article
• Language: English
• Subjects: Annealing; Antimony compounds; Broadband; Carrier transport; Cu9S5; Epitaxial growth; heteroepitaxy; Light irradiation; Optoelectronic devices; orientation; Photometers; post‐annealing; Sb2Se3; Selenides; self‐powered photodetector; Single crystals; Substrates; Thickness
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202308229

Antimony selenide (Sb2Se3) is a promising semiconductor for photodetector applications due to its unique photovoltaic properties. Achieving optimal carrier transport in (001)‐Sb2Se3 by the material of contacting substrate requires in‐depth study. In this paper, the induced growth of Sb2Se3 films from (hk0) to (hk1) planes is achieved on digenite (Cu9S5) films by post‐annealing treatment. The flake‐like and flower‐like morphologies on the surface of Sb2Se3 films are caused by different thicknesses of the Cu9S5 films, which are related to the (hk0) and (hk1) planes of Sb2Se3 surface. The epitaxial growth of Sb2Se3 films on (105)‐Cu9S5 surfaces exhibits thickness dependence. The results inform research into the controlled induced growth of low‐dimensional materials. The device of Sb2Se3/Cu9S5/Si has good broadband response (visible to near‐infrared), self‐powered characteristics, and stability. As the crystalline quality of the Sb2Se3 film increases along the (hk1) plane, the carrier transport is enhanced correspondingly. Under the 980 nm light irradiation, the device has an excellent switching ratio of 2 × 104 at 0 bias, with responsivity, detectivity, and response time up to 17 µA W−1, 1.48 × 107 Jones, and 355/490 µs, respectively. This suggests that Sb2Se3 is suitable for self‐powered photodetectors and related optical and optoelectronic devices. The antimony selenide (Sb2Se3) films achieve the transition from (hk0) to (hk1) plane on the contact substrate of digenite (Cu9S5) films. The ordered arrangement of chained Sb4Se6 appears as (211), (221), (101), (151), (301), and (410) crystal plane by post‐annealing treatment. The different crystal growth in the Sb2Se3 films leads to flake‐ and flower‐like morphologies on the surface.