Bi 2 O 3 monolayers from elemental liquid bismuth

• Published in: Nanoscale 2018-08, Vol.10 (33), p.15615-15623
• Main Authors: Messalea, Kibret A, Carey, Benjamin J, Jannat, Azmira, Syed, Nitu, Mohiuddin, Md, Zhang, Bao Yue, Zavabeti, Ali, Ahmed, Taimur, Mahmood, Nasir, Della Gaspera, Enrico, Khoshmanesh, Khashayar, Kalantar-Zadeh, Kourosh, Daeneke, Torben
• Format: Article
• Language: English
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c8nr03788d

Atomically thin, semiconducting transition and post transition metal oxides are emerging as a promising category of materials for high-performance oxide optoelectronic applications. However, the wafer-scale synthesis of crystalline atomically thin samples has been a challenge, particularly for oxides that do not present layered crystal structures. Herein we use a facile, scalable method to synthesise ultrathin bismuth oxide nanosheets using a liquid metal facilitated synthesis approach. Monolayers of α-Bi2O3 featuring sub-nanometre thickness, high crystallinity and large lateral dimensions could be isolated from the liquid bismuth surface. The nanosheets were found to be n-type semiconductors with a direct band gap of ∼3.5 eV and were suited for developing ultra violet (UV) photodetectors. The developed devices featured a high responsivity of ∼400 AW-1 when illuminated with 365 nm UV light and fast response times of ∼70 μs. The developed methods and obtained nanosheets can likely be developed further towards the synthesis of other bismuth based atomically thin chalcogenides that hold promise for electronic, optical and catalytic applications.