BAND GAP ENERGY CHARACTERISTICS IN MATERIALS

Abstract

Band gap energy is one of the most fundamental parameters in
determining the electronic and optoelectronic properties of a material. The band
gap value is a measure of the energy jump that electrons must make in order to
actively conduct electricity. The greater the band gap value, the greater the energy
required by electrons to conduct electricity.
The difference in band gap values in various materials affects the ability of the
material to conduct electricity or interact with light. Therefore, understanding the
characteristics of band gap energy is very important in the development of various
devices such as semiconductors, photovoltaics, optical sensors, and light-emitting
diodes (LEDs). This article examines the differences in band gap characteristics
in three main types of materials: conductors, semiconductors, and insulators. In
conductors, the band gap does not exist or is very small, allowing electrons to
move freely. Insulators have a very large band gap so they do not conduct
electricity. Semiconductors are in between and have high flexibility to be modified
through doping, structural engineering, and external field applications. The main
focus is given to semiconductors because of their very large role in modern
electronic and optoelectronic devices. The fundamental differences between
direct and indirect band gaps are also discussed. Materials with direct band gaps
such as GaAs or InGaN are very suitable for LED applications because they allow
efficient light emission without the help of phonons. Meanwhile, materials such
as silicon with indirect band gaps tend to be unsuitable for LEDs because their
photon emission efficiency is low. With proper understanding and engineering of
band gap characteristics, the performance of devices such as LEDs can be
significantly improved, both in terms of light efficiency, stability, and the range of
wavelengths produced.