Heterostructures are composite stable semiconductor structures consisting of two or more layers of different materials, one grown on another.

Heterostructures are used to construct quantum devices. Quantum heterostructures are required to have sharp junctions which has sharper density of states, since for quantization the dimensions are require to be comparable to the electron wavelength. The quantum confinement is been done by means of the size restriction which leads to the formation of a set of discrete energy levels at which the carriers can exist.

Short-wavelength light-emitting diodes and diode lasers, and some optoelectronic devices such as high-efficiency photovoltaic cells are some important applications of heterostructures.

While heterostructures properties can be fine tuned by varying the thickness of the composing layers, the most important parameters for a heterostructure are the band-offsets. The band offsets determine how the energy bands of one material line up with the other at an interface formed between two semi-infinite half crystals. They depend in principle on interface orientation and possibly on interface reconstructions and interdiffusion, and the strain state of the materials. The natural band offset is the intrinsic line-up of the two bulk band structures ignoring these real life complications. In case of polar materials, the two materials may have different spontaneous polarizations or polarizations may also be induced by the piezoelectric effect in combination with strain. These lead to interface surface charge densities and electric fields in the layers.

Here we provide information on the band-offsets for pairs of materials and specific information on specific heterostructures.

References:

[1]. Heterojunctions in Wikipedia, Received 11 September 2016, http://en.wikipedia.org/wiki/Heterojunctions