Modeling of GaAs Metal Semiconductor Field Effect Transistor Based Photo Detector for Optical Communication

Abstract

A photodetectors is a solid-state sensor that converts light energy into electrical energy. newlineAccording to Isaac Newton, light energy consists of small packets or bundles of newlineparticles called photons. Albert Einstein, who won the Nobel Prize for the discovery newlineof the photoelectric effect, showed that when these photons hit a metal, they could newlineexcite electrons in it. The minimum photo energy required to generate (excite) an newlineelectron is defined as the work function and the number of electrons generated is newlineproportional to the intensity of the light. The semiconductor photodetectors are made newlinefrom different semiconductor materials such as silicon, germanium, indium gallium newlinearsenide, indium antimonide, and mercury cadmium telluride, to name a few. Each newlinematerial has characteristic bandgap energy (Eg), which determines its light-absorbing newlinecapabilities. Light is a form of electromagnetic radiation, comprising of different wavelengths (and#955;). The range of light spectrum is split approximately as: ultraviolet (0 400 nm); visible (400 1000 nm); near infrared (1000 3000 nm); medium infrared (3000 6000 nm); far infrared (6000 40,000 nm); extreme infrared (40,000 newline100,000 nm). The equation between bandgap energy (Eg) and cutoff wavelength (and#955;c) newlineis (eV) nm Eg 1.24X103 and#955;c and#61501; Photodetectors find various applications in fiber-optic communications (800 1600 nm), spectroscopy (400 nm 6000 nm), laser range finding (400 nm 10,600 nm), photon counting (400 nm 1800 nm), and satellite imaging (200 nm 1200 nm), to name only a few topics. newlineThree kinds of diodes), and (3) photogates are discussed here. Frequently, such detectors need to have high sensitivity, low noise, and high reliability for use in applications. newline