Avalanche photodiode working principle

Avalanche photodiodes provide very sensitive light detection. Operating under reverse bias they use avalanche breakdown to give gain. Compared to regular PIN construction photodiodes, APDs, have an internal region where electron multiplication occurs, by application of an external reverse voltage, and the resultant gain in the output signal . However the structure is optimised for avalanche operation. The main difference of the avalanche .

This article is about avalanche diode working and construction and is similar to Zener diode.

The application of this diode is to protect the circuit.

The types of the photodiodes can be classified based on its construction and functions as follows. One limitation of the regular p-i-n photodiode is the lack of internal gain - an. The operation principle of an APD is based on the conversion of the energy of photons (γ-quanta, ionizing particles) into free charge carriers in the semiconductor bulk and their further multiplication via the process of impact ionization. An example of the APD structure is shown on Figure 1. The basic element of the structure . The prerequisite for this is the application of reverse bias voltage to the APD to broaden the. A diode is two-terminal or two-electrode semiconductor device, which allows the electric current flow in one direction while blocks the electric current flow in.

The detection bandwidth achievable with avalanche diodes can be quite high, although there is an inherent trade-off between bandwidth and amplification factor. In this lecture you will learn the following. Learn about the principle of optical detection.

Know various optical detectors like photodiodes , p-i-n diodes and avalanche diodes. Photon detectors work on the principle of conversion of photons to electrons. For More Video lectures from IIT Professors. The PIN photo diode operates with an applied reverse bias voltage and when the reverse bias is applie the space charge region must cover the intrinsic region. Materials and processing can be adapted to individual customer and product requirements, thus enabling the optimization of parameters such as sensitivity at different wavelengths, speed and capacity.

We will be happy to help you find the ideal technology for your application. Basic characteristics of Si APD. Connection to peripheral circuits. Principle of avalanche multiplication. A high field means that the drift velocity of the electrons flowing through the . This allows each photo-generated carrier to be multiplied by avalanche breakdown, resulting in internal gain within the photodiode, which increases the effective responsivity of .