Pumping intensity dependent surface charge accumulation and redshifted microphotoluminescence of silicon-implanted quartz

The pumping-intensity dependency of nanocrystallite silicon (nc-Si) related microphotoluminescence (μ-PL) from multirecipe Si-implanted quartz is characterized. After annealing at 1100°C for 3h, theμ-PL at 724nm contributed by nc-Si with a diameter of about 4nm is maximized. By increasing the pumping intensity from 10kW∕cm2 to 300kW∕cm2, the μ-PLs of 1 and 3-h-annealed Si-implanted quartz samples are redshifted by <1.2 and 11nm, respectively. The μ-PL of 3-h-annealed sample further redshifts by 2.5nm after pumping at 300kW∕cm2 for h. Such a redshift in PL is attributed to the anomalous quantum Stark effect under strong illumination, which photoionizes the buried nc-Si and initiates an electric field beneath the surface of Si-implanted quartz. The measurement of accumulating charges and voltage drop during illumination primarily elucidate the correlation between redshift in PL and the photoionized nc-Si induced surface electric field.