Direct observation and manipulation of hot electrons at room temperature. Issue 9 (15th December 2020)

• Record Type: Journal Article
• Authors: Wang, Hailu; Wang, Fang; Xia, Hui; Wang, Peng; Li, Tianxin; Li, Juzhu; Wang, Zhen; Sun, Jiamin; Wu, Peisong; Ye, Jiafu; Zhuang, Qiandong; Yang, Zaixing; Fu, Lan; Hu, Weida; Chen, Xiaoshuang; Lu, Wei
• Is Part Of: National science review. Volume 8:Issue 9(2021)
• Publication Date: 2020-12-15
• Subjects: hot electrons -- valley transfer -- photogating -- scanning photocurrent mapping; Science -- Periodicals; 505
• DOI: 10.1093/nsr/nwaa295
• Languages: English
• ISSNs: 2095-5138

Abstract

Abstract: In modern electronics and optoelectronics, hot electron behaviors are highly concerned, as they determine the performance limit of a device or system, like the associated thermal or power constraint of chips and the Shockley-Queisser limit for solar cell efficiency. To date, however, the manipulation of hot electrons has been mostly based on conceptual interpretations rather than a direct observation. The problem arises from a fundamental fact that energy-differential electrons are mixed up in real-space, making it hard to distinguish them from each other by standard measurements. Here we demonstrate a distinct approach to artificially (spatially) separate hot electrons from cold ones in semiconductor nanowire transistors, which thus offers a unique opportunity to observe and modulate electron occupied state, energy, mobility and even path. Such a process is accomplished through the scanning-photocurrent-microscopy measurements by activating the intervalley-scattering events and 1D charge-neutrality rule. Findings here may provide a new degree of freedom in manipulating non-equilibrium electrons for both electronic and optoelectronic applications. Abstract : A distinct approach to artificially (spatially) separate hot electrons from cold ones, which thus provides a new degree of freedom in manipulating nonequilibrium electrons for both electronic and optoelectronic applications.