High-Performance Phototransistors by Alumina Encapsulation of a 2D Semiconductor with Self-Aligned Contacts

Liang, Guangda; Wang, Yiming; Zhang, Jiawei; Kudrynskyi, Zakhar R.; Kovalyuk, Zakhar; Patanè, Amalia; Xin, Qian; Song, Aimin

Abstract

2D semiconductors are promising candidates for next generation electronics and optoelectronics. However, their exposure to air and/or resists during device fabrication can cause considerable degradation of material quality, hindering their study and exploitation. Here, field effect transistors (FETs) are designed and fabricated by encapsulation of the 2D semiconductor indium selenide (InSe) with alumina (Al2O3) and by self-aligned electrical contacts. The Al2O3-film is grown directly on InSe immediately after its exfoliation to provide a protecting capping layer during and after device fabrication. The InSe-FETs exhibit a high electron mobility of up to ≈103 cm2 V−1 s−1 at room temperature for a 4-nm-thick InSe layer, a low contact resistance (down to 0.18 kΩ) and a high, fast, and broad-band photoresponsivity. The photoresponsivity depends on the InSe-layer thickness and photon wavelength, reaching a value of up to 108 A W−1 in the visible spectral range, at least one order of magnitude larger than previously reported for similar photodetectors. The proposed fabrication is scalable and suitable for high-precision pattern definition. It could be extended to other 2D materials and multilayer structures where alumina could also provide effective screening of the electric field induced by polar molecules and/or charged impurities present near the surface of the 2D layer.

Citation

Liang, G., Wang, Y., Zhang, J., Kudrynskyi, Z. R., Kovalyuk, Z., Patanè, A., …Song, A. (2022). High-Performance Phototransistors by Alumina Encapsulation of a 2D Semiconductor with Self-Aligned Contacts. Advanced Electronic Materials, 8(5), Article 2100954. https://doi.org/10.1002/aelm.202100954

• Journal Article Type: Article
• Acceptance Date: Dec 16, 2021
• Online Publication Date: Jan 7, 2022
• Publication Date: May 1, 2022
• Deposit Date: Dec 17, 2021
• Publicly Available Date: Jan 8, 2023
• Journal: Advanced Electronic Materials
• Electronic ISSN: 2199-160X
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 8
• Issue: 5
• Article Number: 2100954
• DOI: https://doi.org/10.1002/aelm.202100954
• Keywords: Electronic, Optical and Magnetic Materials
• Public URL: https://nottingham-repository.worktribe.com/output/7022796
• Publisher URL: https://onlinelibrary.wiley.com/doi/10.1002/aelm.202100954
• Additional Information: This is the peer reviewed version of the following article: Liang, G. D., Wang, Y. M., Zhang, J. W., Kudrynskyi, Z., Kovalyuk, Z., Patanè, A., Xin, Q., Song, A. M., High-Performance Phototransistors by Alumina Encapsulation of a 2D Semiconductor with Self-Aligned Contacts. Adv. Electron. Mater. 2022, 2100954, which has been published in final form at https://doi.org/10.1002/aelm.202100954. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.