Abstract:Stimulated surface-and edge-emission were investigated for ZnO thin films grown epitaxially by pulsed laser deposition. The lasing threshold was 0.32 MW/cm 2 for surface pumping and 0.5 MW/cm 2 for edge pumping, which is significantly lower than thresholds observed previously. A modified variable stripe length method was used to measure the gain, which was 1369 cm -1 for Nband emission. Losses were measured using the shifting excitation spot method and values of 6.2 cm -1 and 6.3 cm -1 were found for the N-band and P-band, respectively. The measured gain and loss were the highest and lowest (respectively) ever reported for ZnO films.

Synthesis of ultra-thin, well-aligned, monocrystalline, highly luminescent ZnO nanowires on polystyrene beads as templates.

of about 5.3 meV which shows a good agreement to the ambient thermal energy at 70 K. Traditionally, ZnO:Zn with high defect emission can be created directly through the use of very high temperature processes. We have shown here that through the sulfurization/desulfurization process strong defect emission can be induced at lower temperatures with greater control over degree of defects induced. This is an important advancement, particularly in the field of earth-abundant phosphors. Experimental Details and Analysis Method ZnO nanowires were prepared by chemical bath deposition on quartz and silicon substrates. 0.035 M Zinc acetate was dissolved in 750 mL of DI water. 9 ml of ammonium hydroxide was added to this solution. The ZnO seed layer pre-coated quartz and silicon substrates were immersed in this solution for one hour at 87 °C (details of the deposition technique have been reported elsewhere 28). The desulfurized ZnO was prepared via two steps, namely sulfurization and desulfurization, in a chemical vapor deposition (CVD) reactor (a horizontal tube furnace).