ELECTROCHEMICAL CAPACITANCE-VOLTAGE PROFILING OF NONUNIFORM DOPED GALLIUM ARSENIDE LIGHT-EMITTING HETEROSTRUCTURES
The light-emitting heterostructures with single and multiple quantum wells based on GaAs/InGaAs were investigated by means of electrochemical capacitance-voltage (ECV) technique. The capacitance-voltage characteristics are measured, the free charge carrier depth distributions are obtained, the spatial arrangement and quantum wells filling degree are determined. As an example of heterostructures with a single QW, the limitations and difficulties of capacitance-based techniques while profiling undoped QWs located near the metallurgical boundary of the p-n junction are considered. In particular, the phenomena associated with the Debye spreading are discussed in detail; the dependence of the space-charge region magnitude on the doping level is given and analyzed. The capacitance-voltage characteristic evolution (transition of 1/C2 angle through 90°) during ECV-profiling of nonuniformly-doped p-n heterostructures is presented. In the heterostructure with MQW the concentration response from six QWs is recorded, thus the charge carrier distribution in the active area of the heterostructure was spatially resolved.
Authors: G. E. Yakovlev, V. I. Zubkov, V. G. Litvinov, A. V. Ermachikhin
Direction: Physical Phenomena in a Solid Body, Liquids and Gases
Keywords: Electrochemical capacitance-voltage profiling, ECV, LED, GaAs, QW, MQW, QD, C-V, nonuniform doping
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