In 2 Si 2 S 3 X 3 (X = S, Se, Te) Janus monolayers: from magnetic element-free spin-Hall transistor to sustainable energy generation

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2024-02, Vol.12 (5), p.1888-1896
• Main Authors: Mohanta, Manish Kumar, Jena, Puru
• Format: Article
• Language: English
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/D3TC03805J

Conventional spintronics uses ferromagnets for spin generation and detection; however, recent experiments have demonstrated highly efficient ferromagnet-free spin-Hall transistors. In this work, we propose a novel multiatomic direct band gap Janus In 2 Si 2 S 3 Te 3 monolayer as a channel semiconductor that exhibits a finite spin-Hall conductivity with high charge carrier mobility of 2772 cm 2 V −1 s −1 at room temperature. In this model device, a pure spin current can be generated from the charge current using the spin-Hall effect whereas the inverse spin-Hall effect can be used to generate a Hall voltage. Further, this monolayer is predicted to possess a large out-of-plane piezoelectric coefficient of 160 pm V −1 originating from crystal asymmetry and low elastic stiffness. A three-fold enhancement in solar to hydrogen efficiency is obtained for the Janus In 2 Si 2 S 3 Se 3 monolayer (∼7.32%) compared to its pristine In 2 Si 2 S 6 monolayer (∼2.44%). Moreover, this work provides detailed theoretical insights into the emergent electronic and piezoelectric properties of multi-atomic In 2 Si 2 S 3 X 3 (X = S, Se, Te) monolayers. Experimental synthesis of multi-atomic CuInP 2 S 6 nanosheets paves the way for the exploration of the proposed semiconductors in spintronics, piezotronics, and water splitting.