CAREER NETWORK World's one of the largest Research Career Network Benefits Academic & Industry jobs Project funding Visiting faculty positions Visiting scientist positions Invited talks and more... Register FREE Physics Express 2011, 1: 27 Research Article Optical Gain and Threshold Current Density of a P-Doped ZnO–MgZnO Quantum Dot Lasers Hussein B. AL-Husseini Nassiriya Nanotechnology Research Laboratory (NNRL), Physics Department, Science College, Thi-Qar University, Nassiriya, Iraq Abstract The exciton states, optical gain spectra and threshold current density of a p-doped and an undoped ZnO/MgZnO wurtzite (WZ) quantum dot QD laser are calculated. Effects of QD size and WL composition are studied It is shown that The exciton binding energy is reduced with increasing the dot size or decreasing Mg content. ZnO/Mg0.34Zn0.66O QDs are less sensitive to size fluctuations. ZnO wurtzite QD structures shown to be able for broad band laser applications. Threshold current density increases with reducing QD size. Our numerical results also studies QD size and WL composition on exciton states and optical properties of WZ ZnO/MgZnO QD. Keywords Quantum Dot (QD); Semiconductor Lasers; Exciton States; Optical Gain; Threshold Current Density