DETERMINATION OF CARRIER AND IMPURITY PROFILES IN DOPED N-TYPE QUANTUM-WELL STRUCTURES

Because of the inherent potential profile in multiple-quantum-well and superlattice structures, there is an effective redistribution of carr iers between barriers and wells. In this work it is shown that through a combination of capacitance-voltage (C-V), deep-level transient spec troscopy, photoluminescence and Hall effect measurements a comprehensi ve evaluation of the carrier profiles and barrier purity in n-type mat erial can be obtained. A detailed theoretical analysis of the C-V data is also presented which includes the effects of barrier depletion, th e Debye tail and penetration of the electron wavefunction into the bar rier layers.