Impact of photoexcitation on secondary electron emission: A Monte Carlo study

Understanding the transport of photogenerated charge carriers in semiconductors is crucial for applications photovoltaics, optoelectronics, and photo-detectors. While recent experimental studies using scanning ultrafast electron microscopy (SUEM) have demonstrated that local change secondary emission induced by photoexcitation enables direct visualization photocarrier dynamics space time, origin corresponding image contrast still remains unclear. Here, we investigate impact on emissions from a Monte Carlo simulation aided time-dependent density functional theory. Particularly, examine two photoinduced effects: generation photocarriers sample bulk surface photovoltage (SPV) effect. Using doped silicon as model system focusing primary energies below 1 keV, found both hot effect immediately after SPV play dominant roles changing yield (SEY), while distribution leads to negligible SEY. Our work provides insights into electron–matter interaction under photo-illumination paves way toward quantitative interpretation SUEM contrasts.