How Does The Bandgap Of Aluminium Selenide Vary With Temperature?

Aluminum selenide (AlSe) is a semiconductor material with a specific energy gap between its valence and conduction bands, known as the bandgap. The bandgap determines the minimum amount of energy required to promote an electron from the valence band to the conduction band, allowing it to conduct electricity.

The bandgap of aluminum selenide decreases with increasing temperature, following the empirical relation:

Eg(T) = Eg(0) - αT²/(T + β)

where Eg(0) is the bandgap energy at absolute zero temperature, α is a material constant, and β is a temperature-dependent constant related to the Debye temperature of the crystal lattice.

The decrease in bandgap with temperature can be explained by the increase in lattice vibrations or phonons, which can disturb the bonding between atoms and reduce the effective energy required to excite electrons across the bandgap. As the temperature increases, more phonons are excited, leading to a greater reduction in the bandgap.

This effect is also known as bandgap narrowing, and it can have practical implications for the performance of semiconductor devices based on AlSe. At high temperatures, the decrease in bandgap could increase the leakage current and reduce the efficiency of devices such as solar cells or transistors. Hence, it is important to take into account the temperature dependence of the bandgap when designing and optimizing such devices.