bredbandgapmaterial
Bandgap materials are semiconductors in which the energy separation between the valence band and the conduction band, known as the bandgap, governs both electrical transport and optical response. The bandgap energy (Eg) determines the minimum photon energy that can be absorbed to excite an electron across the gap, and it varies with temperature and composition. Materials with different Eg values are chosen for specific optoelectronic or electronic applications.
Bandgaps are classified as direct or indirect. In direct-bandgap materials, the conduction-band minimum and valence-band maximum
Common bandgap materials include silicon (indirect, Eg about 1.12 eV at room temperature), gallium arsenide (direct,
Bandgap engineering employs alloying, strain, and quantum confinement to tailor Eg. Heterostructures and quantum wells confine
Applications span electronics, light-emitting devices, lasers, solar cells, and photodetectors. The bandgap concept is central to