Electron-hole pairs are produced by
Right Answer is:
Electron-hole pairs are produced by recombination.
⇒ An intrinsic semiconductor is a semiconductor crystal in which electrical conduction arises due to thermally excited electrons and holes.
⇒ In semiconductors, a single event of covalent bond breaking leads to the generation of two charge carriers, an electron in the conduction band and a hole in the valence band. The process may be represented as
Covalent Bond + Thermal Energy ⇒ (Electron + Hole)Pairs
⇒ As electron and hole are produced simultaneously, the process is called electron-hole pair generation.
⇒ In the process of generation, a covalent bond is broken and a bound electron is transformed into a free electron. Thermal energy is one of the agents which causes pair generation.
⇒ It is likely that the electron in the conduction band may lose its energy due to collision with other particles in the lattice and fall into the valence band.
⇒ When a free electron falls into a valence band, it merges with a hole. This process is called recombination.