All Epitaxial Mode and Current Confined Semiconductor Laser Using Selective Fermi Level Pinning

All - Epitaxial Mode - and Current - Confined GaAs - Based Vertical - Cavity Surface - Emitting Lasers

Acknowledgements I would like to express my deep appreciation to my supervisor, Dr. Dennis G. Deppe, for leading me into the exciting semiconductor laser field and for his inspiring and insightful guidance throughout this course of research. In addition, I would like to thank my excellent committee members, Dr. learned semiconductor processing and MBE crystal growth 101 from them, and also rece...

Fermi level pinning and differential efficiency in GaInP quantum well laser diodes

Fermi-Level Pinning by Misfit Dislocations at GaAs Interfaces

Fermi-level pinning by misfit dislocations at GaAs interfaces has been investigated. n -GaInAs was used to control the misfit dislocation density by varying of composition and epilayer thickness. interfaces with zero or low dislocation densities are Ohmic to current flow, and become rectifying with increasing dislocation density. The "Schottky barrier height" increases with dislocation density ...

Fermi-level pinning can determine polarity in semiconductor nanorods

First-principles calculations of polar semiconductor nanorods reveal that their dipole moments are strongly influenced by Fermi-level pinning. The Fermi level for an isolated nanorod is found to coincide with a significant density of electronic surface states at the end surfaces, which are either mid-gap states or band-edge states. These states pin the Fermi level, and therefore fix the potenti...

Two-Dimensional Numerical Simulation of Fermi- Level Pinning Phenomena Due to DX Centers in AlGaAs/GaAs HEMT’s

Fermi-level pinning phenomena due to DX centers in AlGaAs/GaAs HEMT’s are analyzed using two-dimensional numerical simulation based on a drift-diffusion model. A DX center model is introduced assuming Fermi-Dirac statistics for ionized donor density with the aluminum mole fraction dependence of the deep-donor energy level. The calculated results reveal that the decrease in transconductance of A...