Definition of quantum well: If one dimension of the material is reduced to nano range while the other two dimensions remain large, then the material or structure is called quantum well. Quantum well is also called nanolayers.

Preparation of quantum well:

The quantum well in nanotechnology is formed by sandwiching a material (fore example GaAs) between the two layers of another material having broader gap (For example aluminium arsenide). The layers are prepared by the chemical vapor deposition or epitaxy.

In nanotechnology, a quantum well is like a potential well in which the carrier particles are trapped and it took place when the thickness of the well is comparable to the de Broglie wavelength of the carriers.

Application of quantum well:

1. Quantum wells are used in diode lasers.
2. Quantum well are used as infra red detectors.

I hope you have understood the meaning of quantum well in nanotechnology.