Abstract |
The rapid evolution of semiconductor technology and physics in recent years has led to the development of optoelectronic devices of micrometer dimensions. The improvement of precision in deposition technology has allowed the development of high quality semiconductor devices. In the field of optoelectronic devices, increased quality is directly related to a better utilization of carriers for the production of light.
The development of the first vertical cavity surface emitting laser (VCSEL) with the use of Bragg mirrors in 1979 and subsequent investigations in the field, contributed to better understanding of the physics of carriers in heterostructures and their interaction with cavity photons.
The objective of this thesis was to optimize the production of light in microcavities by better utilization of carriers. In a previously studied microcavity light emitting diode (917) it was observed that carriers recombine outside the active region. This observation led to the development of an optimized structure (943), which is supposed to lead to a better carrier confinement.
Here, we utilized reflectance and photoluminescence measurements for optical characterization of the optimized structure. After the appropriate processing and diode fabriacation, spectra of electroluminescence and current-voltage characteristics at different temperatures were obtained. An improvement in carrier confinement is observed on the active region of 943 microcavities compared to 917 microcavities, however carrier losses from the cavity were still significant. These losses are attributed to the high resistance of the holes in the p+ DBR in contrast with the great mobility of electrons. Finally, for further optimization, modeling of acceptors of delta-like distribution at appropriate positions of a p+ DBR was undertaken using the program Next Nano3, in order to reduce the resistance of the p+ DBR during hole injection.
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