Fast Response - Photon Sensor - Agent [Weikewei]

Photon sensorIt is the use of certain semiconductor materials to generate photon effects under human irradiation, causing changes in the electrical properties of the material. By measuring changes in electrical properties, the strength of infrared radiation can be determined. Infrared sensors made using photon effects are collectively referred to as photon sensors.

According to the working principle of light in sensors, they can generally be divided into internal photoelectric and external photoelectricsensorThere are two types, the former is further divided into three types: photoconductive sensors, photovoltaic sensors, and opto magneto electric sensors.

1) External photoelectric sensor (PE device)

When light radiation shines on the surface of certain materials, if the photon energy of the emitted light is large enough, it can cause the electrons of the material to escape the surface and emit electrons outward. This phenomenon is called the external photoelectric effect or photoelectron emission effect. Photodiodes, photomultiplier tubes, and other electronic sensors belong to this type. itsThe response speed is relatively fastUsually only takes a few nanoseconds. But the escape of electrons requires a large amount of photon energy, which is only suitable for use in the near-infrared radiation or visible light range.

2) Photoconductive sensor (PC device)

When infrared radiation is irradiated on the surface of certain semiconductor materials, some electrons and holes in the semiconductor material can change from their originally non-conductive bound state to a conductive free state, increasing the conductivity of the semiconductor. This phenomenon is called photoconductivity. Sensors made using the phenomenon of photoconductivity are called photoelectric sensorsConductivity sensorUsing a photoconductive sensor and applying a certain bias voltage as described above, otherwise the response rate will decrease, noise will be high, and the response band will be narrow, resulting in damage to the infrared sensor.

3)Photovoltaic sensor（PU devices)

When infrared radiation is irradiated on the pn junction of certain semiconductor materials, under the action of the electric field inside the junction, free electrons move towards the n region and holes move towards the p region. If the pn junction is open, an additional potential is generated at both ends of the pn junction, called the photo induced electromotive force. The sensor made using this effect is called a photovoltaic sensor. The commonly used materials are indium arsenide (InAs), indium antimonide (InSb), mercury cadmium telluride (HgCdTe), lead tin telluride (PbSnTe), and several others.

4)Optical magneto electric sensor(PEM device)

When infrared radiation is irradiated on the surface of certain semiconductor materials, electrons and holes on the material surface will diffuse inward. If they are subjected to a strong magnetic field during diffusion, the electrons and holes will each deviate to one side, resulting in an open circuit voltage. This phenomenon is called the photoelectric effect. The infrared sensor made using this effect is called a photoelectric magnetic sensor. Optical magneto electric sensors do not require refrigeration, with a response band of up to 7 μ m, a small time constant, fast response speed, no need for bias voltage, extremely low internal resistance, low noise, and good stability and reliability. However, its low sensitivity and difficulty in producing low-noise preamplifiers have affected its use.