Quantum confinement of electronic states

In practice the well depth is not infinite and the subband energies are reduced because the electron wavefunction penetrates into the barrier material. The wavefunction in the z direction is. 

Observation of the subbands is the crucial test of quantization effects and the most common experimental measurement is optical absorption. The subband discontinuities give a joint density of states with a stepped 

Many attempts have been made to observe the quantization effects in a-Si H. Fig. 9.25 shows some early measurements of the optical absorption edge in a-Si H/nitride multilayers (Abeles and Tiedje 

More recent measurements have identified the subband thresholds by modulated absorption and by resonant tunneling. The thermo- 

The derivative spectra should have sharp features at the subband thresholds which are easier to detect than in the normal optical spectrum. 

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