Direct Probing of Transient Photocurrent Dynamics in p-WSe2by Time-Resolved Scanning Tunneling Microscopy

• DOI: 10.7567/apex.6.016601
• Publication Date: 2013-01-24T01:35:39Z
• Authors: Shoji Yoshida; Yasuhiko Terada; Munenori Yokota; Osamu Takeuchi; Yutaka Mera; Hidemi Shigekawa
• Keywords: Photocurrent; Nanosecond; Photoconductivity; Surface Photovoltage

We have carried out time-resolved scanning tunneling microscopy on a layered semiconductor with an indirect bandgap, p-WSe2, and the dynamics of nonequilibrium photocurrent generated by ultrashort-pulse-laser excitation was analyzed. The reflecting flow excited photocarriers at surface, which is determined balance between diffusion rates, successfully probed. Furthermore, excess minority carriers transiently trapped surface for few nanoseconds, produce transient photovoltage cannot be detected conventional methods, were directly observed evaluated.