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hokhani
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How a bound electron-hole pair (exciton) can move together while the velocity of the free electron in the conduction band is opposite to that of the corresponding hole in the valence band?
By this, do you mean that my earlier comment (according to the picture) is correct?Cthugha said:On the other hand, you can excite free electrons and holes which may afterwards lose energy and form excitons. But in this case the electron/hole created by one photon are not necessarily the ones which will form the exciton.
hokhani said:By this, do you mean that my earlier comment (according to the picture) is correct?
Excitons are a type of quasiparticle that consists of an electron and a hole bound together by the Coulomb force. They behave like a single particle and are created when an electron is excited to a higher energy state, leaving behind a positively charged hole in the lower energy state.
Excitons move through a material by the opposite movements of the electron and hole. The electron moves in the direction of the applied electric field, while the hole moves in the opposite direction.
Excitons play a crucial role in the optical and electronic properties of materials. They can transfer energy and carry electrical charge, making them important for applications in optoelectronics, photovoltaics, and light-emitting devices.
Excitons can be created through various processes, such as absorption of light or injection of electrons and holes. They can be destroyed through recombination, where the electron and hole recombine and release energy in the form of light or heat.
Yes, excitons can be manipulated by controlling the properties of the material they are in, such as the strength of the electric field or the presence of impurities. This allows for the tuning of excitons' properties, which is important for designing new materials with desired functionalities.