2017 年 60 巻 10 号 p. 388-391
A system for time-resolved photoemission electron microscopy (TR-PEEM) conducted with femtosecond laser pulses has been developed to explore the photogenerated electron dynamics on semiconductor surfaces. Attained space and time resolutions were 100 nm and 100 fs, respectively. The present manuscript introduces the TR-PEEM system, and also reports the observation of different photogenerated electron lifetimes in different nanoscale structural defects randomly distributed on a semiconductor surface. The results were explained based on Schockley-Read-Hall (SRH) model relating the carrier recombination time and the defect state density. The defect state density in each defect was successfully estimated.