Analysis of transient signal broadening of silicon-based photodiodes irradiated by nanosecond laser

Abstract

To investigate the saturation characteristics of silicon-based optoelectronic devices caused by short-pulse laser irradiation, an Nd:YAG laser with a wavelength of 1064 nm and two typical silicon-based photodiodes, PN and PIN, were employed to build an experimental system to measure the transient response signal of the device. The change. The experimental results demonstrate that with the increase of laser energy density, the nonlinear saturation of the two devices occurs, and the response time is significantly increased. This is a response degradation phenomenon for the response of the device and the signal after the saturation of the two devices. By analyzing the rising edge, half-height width, and bottom width of the characteristic quantity, it can be found that the broadening of the two devices is mainly due to the broadening of the falling edge of the response signal. However, the broadening of the PIN-type photodiode after laser irradiation is compared with that of PN. Type photodiodes remain more remarkable. Through the analysis of carrier dynamics, when the signal is restored, the movement of carriers is affected by a large number of photogenerated carriers after the laser irradiation ends, affecting the drift movement and space charge region during the bipolar transport of carriers. The width of the two devices attenuates the speed when the signals of the two devices are restored, leading to the saturation caused by the laser irradiation of the two devices