Effect of optical excitation level on the MSM-detector high-speed response

摘要

High-speed response of the metal-semiconductor-metal (MSM) detectors is analyzed. Effect of optical excitation level on the MSM-photodetector performance is discussed. At low excitation level the detector speed of response is limited by parasitic capacitance of interdigitated diode structure and by the transit time of the photogenerated carriers. At high excitation level the detector speed of response is limited by the field screening caused by the space-charge of the holes. The impulse response of GaN MSM-detector is compared favorably with GaAs MSM-device.