Plasma-optimized contact for high-performance PdSe2 nanoflake-based field-effect transistors

• Published in: Applied physics letters 2023-07, Vol.123 (4)
• Main Authors: Zha, Jiajia, Liu, Handa, Wang, Huide, Li, Siyuan, Huang, Haoxin, Xia, Yunpeng, Ma, Chen, Yang, Peng, Zhang, Zhuomin, Yang, Zhengbao, Chen, Ye, Ho, Johnny C., Tan, Chaoliang
• Format: Article
• Language: English
• Subjects: Air plasma; Applied physics; Contact resistance; Current carriers; Field effect transistors; High resolution electron microscopy; Optoelectronic devices; Selenium; Semiconductor devices
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/5.0160944

Low-resistance contact has long been pursued in the two-dimensional (2D) electronic/optoelectronic device community. Still, an economy-efficient method highly compatible with the conventional 2D device fabrication process in laboratory remains to be explored. Herein, we report a plasma-optimized contact strategy for high-performance PdSe2 nanoflake-based field-effect transistors (FETs). Selenium vacancies created by air plasma can introduce p-type doping in the contact area, thus optimizing the device performance. The effect of plasma treatment on PdSe2 nanoflake is corroborated by high-resolution transmission electron microscopy, energy-dispersive x-ray spectroscopy spectrum, atomic force microscopy, and Kelvin probe force microscopy. The PdSe2 FET with plasma-optimized contact exhibits significantly improved field-effect carrier mobilities, current on/off ratios, and reduced contact resistance than that without plasma treatment fabricated from the same PdSe2 nanoflake. Moreover, this strategy has also been proven effective to prepare high-performance FETs based on 2D WSe2 and MoSe2 nanoflakes, further demonstrating its application prospect.