Direct Bandgap Semiconductor

A direct bandgap semiconductor is a material where electrons can directly transition between energy levels in the conduction and valence bands by absorbing or emitting a photon, without needing extra energy or assistance. This property makes such materials ideal for optoelectronic devices like LEDs and laser diodes because they efficiently produce light. In contrast, indirect bandgap semiconductors require additional interactions, such as phonons (vibrations in the crystal lattice), to emit light, making them less suitable for these applications. Examples of direct bandgap semiconductors include gallium arsenide (GaAs) and indium phosphide (InP).