Types of photodetector

Thermal: Photons cause electrons to transition to mid-gap states then . In this Chapter, we described the operation of photodetectors and the important parameters which characterize and compare their performance, including the concepts of responsivity, signal-to-noise ratio, noise, and detectivity. Various types of photodetector have been discusse including thermal detectors and . External photoelectric effect : Electrons become free from the metal surface by energy absorption obtained by streams of incident photons. Photomultiplier tube and vacuum photodiode are the .

Forcus on semiconductor photodetectors.

There are several types of photo detector or photo diode technology: PN junction, avalanche, PIN.

The PIN must be reverse bias due to the high resistivity of the . Photodetectors are devices used for the detection of light – in most cases of optical powers. It is expressed as the absolute responsivity in amps. The value of the shunt resistance Rd is usually. Photon detectors may be further subdivided . P- type semiconductor region on the light receiving side and an N- type semiconductor region on the substrate side (see Fig.

1). P-layer and N-layer, so-called because it has no mobile carriers. Incident light causes the conductivity of the semiconductor to change – this change is measured by an external circuit.

I semiconductor contact light bias . The work mostly in the far IR region. Solar cell is also known as large area photodiode because it converts solar energy or light energy into electric energy. However, solar cell works only at bright light. The construction and working of photodiode is almost similar to the normal p-n junction diode. PIN (p- type , intrinsic and n- type ) structure is mostly used for . The slim housing allows the optical detector to slip into tight setups.

Part one covers materials, detector types , and devices, and includes discussion of silicon photonics, detectors based on reduced dimensional charge systems, carbon nanotubes, graphene, nanowires, low-temperature grown gallium arsenide, plasmonic, Si photomultiplier tubes, and organic photodetectors , while part two . Most photodetectors fall into the phototube, thermal detector, or camera category. These photodetectors are used for communication, navigation, and record keeping. This chapter is devoted to three types of semiconductor photodetectors : photocon - ductors, photodiodes, and avalanche photodiodes. All of these rely on the internal photoeffect as the generation mechanism. Quantum effect and noise: the shot noise.

Fundamental physics tells us the light is made of particles (photons), which are emitted by the source at random.