The net parameter refers to the constant distance of the unit cells or "dimension of each cell" with respect to its crystal structure, so in a cubic we have a = b = c. Three-dimensional structures or networks generally have three network parameters, a, b, and c. However, in the special case of simple cubic networks, all parameters are the same, which we refer to as a. In the same way, in the hexagonal crystalline structures, the parameters a and b are equal, so we will only consider a and c.
In epitaxial growth, the network parameter is a measure of the structural compatibility between different materials.
Since the network parameters have length dimensions, their unit in the international system is the meter. However, they often occur in submultiples such as nanometer or angstrom.
Matching network parameters is important for growing thin layers of one material over another; when these parameters are different irregularities are formed in the layer and it becomes impossible to grow new layers without defects.
The matching of network parameters between two semiconductor materials allows to form a region with a different forbidden bandwidth without changing the crystal lattice. This builds LEDs and laser diodes.
For example, GaAs, AlGaAs and AlAs have almost identical network parameters, making it possible to grow layers of any thickness one above the other.
Network parameters can be measured by X-ray diffraction.
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