Subband structure

A6.4 Luttinger and Bir-Pikus parameters of GaN and AIN A6.5 Electron and hole effective masses of GaN and AIN A6.6 Deformation potentials of GaN and AIN A6.7 Momentum matrix elements of GaN A6.8 Subband structures of GaN/AlGaN quantum wells A6.9 Optical gain of bulk GaN and GaN/AlGaN quantum wells... 

Experimentally, we can introduce a built-in strain in an epitaxial layer by growing it on a lattice mismatched substrate. As long as the mismatched epitaxial layer is below the critical thickness, the produced strain is uniform and no dislocations are induced. As a result, the in-plane lattice constant of the epitaxial layer is fitted to that of the substrate, and the out-of plane lattice constant is adjusted to a new lattice constant according to the Hook law. Then, the subband structure is modified by introducing a built-in strain, and the strain has a dramatic influence on the electronic properties of the system. Theoretically, we can easily include the strain effect in the k.p theory. 

FIGURE 1 Valence subband structures of the unstrained wurtzite GaN/Al02Gao8N single quantum wells, with the well lengths Lz being (a) 30 A, and (b) 50 A... 

FIGURE 5 Valence subband structure of strained wurtzite GaN/Al02GaogN single quantum wells, with 1.0% uniaxial tensile strain along the x-direction, along (a) the ka and (b) the ky directions,... 

FIGURE 6 Valence subband structures of the strained zincblende GaN/Alo2Gao 8N single quantum wells with (a) 0.5% compressive, and (b) 0.2% tensile biaxial strains, with the well length Lz being 40 A. 

Fig. 9.23. Illustration of the subband structure and density of states distribution of a quantum well.

Wherever this is applicable in rotational fine structure analysis, the customary approach involves analyzing the spectra in terms of a near prolate or oblate top. Deviations from this approximation decrease with increasing quantum number K. For a more extensive discussion, for example of the subband structure in symmetric top spectra, the reader is referred to Allen and Cross (1963). 

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