In this study used the metal-semiconductor diode as IR photodetector, and through the material, device structural and operation bias selection, high response and fast switching can be achieved. The response can be improved by increasing the doping concentration of the semiconductor material. The doping concentration can be increased by varying the temperature of the semiconductor material, and the device structure can be changed to increase the response speed. The operation bias can be adjusted to produce a higher output signal. The metal-semiconductor diode can be used to detect infrared light and has a relatively low power consumption compared to other infrared photodetectors. The experiment result shown that can reach 1.294 mA/W.