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A very low indium content (35 cation % In) a-IZO film, denoted as IZO35/65 or a-ZIO, was fabricated at room temperature. The effect of aluminum (Al) incorporation in IZO35/65 was studied systematically, and reasonably high electrical conductivity and optical transmittance were obtained. After Al doping to an optimum extent, the conductivity was interestingly increased 3 times higher than that of a-ZIO, and this effect could not be attributed to the formation of Al clusters as a further increase in Al led to a significant drop in conductivity. Nonlinear and U-shape resistivity-temperature relationship was observed for some Al doped samples. In addition, an obvious conductivity increase accompanying by the Al2O3 nano-crystallites formation was observed, which provided new evidence to the insulator-metal transition model reported by Nagarajan et al. [Nature Mater. 7, 391 (2008)] recently. [ABSTRACT FROM AUTHOR]

The controllable formation of zinc oxide ( ZnO) nanostructures and nanowires by a cheap and environmental friendly fabrication method of simply subjecting metallic zinc films in sodium chloride ( NaCl) solution at 170°C from 3 to 15 h under hydrothermal conditions is demonstrated in this study. Scanning electron microscopy ( SEM) and X-ray diffraction ( XRD) indicate that ZnO films with different morphologies are obtained: from a film with network of circular pores to a film with nanowire-like network with bigger pores. It is observed that heating duration has an effect on its photoluminescence ( PL) properties. Ultraviolet emission is observed for all ZnO films. Green emission surfaces after heating for 6 h, which subsequently disappears after 15 h of heating. It is suggested that the morphology change over different heating durations is responsible for the rise and subsequent decline in green emissions. Lastly, the growth mechanism behind zinc oxidation and morphology change is proposed and investigated with the aid of experimental method. It is verified that pitting corrosion is responsible for the growth mechanism here. [ABSTRACT FROM AUTHOR]

Al-doped ZnO (AZO) films with high transmittance and low resistivity were achieved on low temperature substrates by radio frequency magnetron sputtering using a high temperature target. By investigating the effect of target temperature (TG) on electrical and optical properties, the origin of electrical conduction is verified as the effect of the high TG, which enhances crystal quality that provides higher mobility of electrons as well as more effective activation for the Al dopants. The optical bandgap increases from 3.30 eV for insulating ZnO to 3.77 eV for conducting AZO grown at high TG, and is associated with conduction-band filling up to 1.13 eV due to the Burstein-Moss effect. [ABSTRACT FROM AUTHOR]

Optical properties of ZnCdO/ZnO single quantum well (SQW) grown on c-sapphire substrate by pulsed laser deposition were investigated. Temperature dependent photoluminescence (PL) measurement was performed from 10 to 300 K to study the carrier localization effect and peak evolution. The LO-phonon replicas up to third order with Huang-Rhys factor of 0.17 were observed. The SQW exhibited very strong PL from the well layer and extremely weak emission from the ZnO barriers, indicating high quality interfaces and highly efficient relaxation. [ABSTRACT FROM AUTHOR]

Surface plasmon (SP) mediated emission from highly ordered Au-nanopattern–capped ZnCdO film has been studied by temperature-dependent photoluminescence (TDPL) from 10 to 300 K. It is found that the bandgap emission from Au-capped ZnCdO is stronger than that of bare ZnCdO throughout the entire temperature range owing to SP coupling and surface modification. The TDPLs of ZnCdO films with and without Au coatings exhibit an inconspicuous S-shape in the plot of emission peak energy (Ep) vs. temperature, signifying a weak carrier localization effect: Ep redshifts in the temperature range of 10–80 K, blueshifts in the range 80–140 K, and redshifts again in the range 140–300 K. It is interesting to find that the temperature-dependent behavior of the enhancement ratio can be divided into three temperature ranges. In the low- and high-temperature ranges, the enhancement ratio is not significantly changed with temperature. However, in the medium-temperature range, the enhancement ratio increases monotonically with temperature due to the excitons delocalization from the potential minima. These results indicate that excitons delocalization is an important prerequisite of the efficient plasmonic enhancement for SP mediated emission from ZnCdO system. [ABSTRACT FROM AUTHOR]

We present on a systematic study of the contribution of surface plasmon (SP) coupling and light extraction toward emission enhancement of Platinum (Pt) nano-patterns capped MgZnO films. Time resolved Photoluminescence (PL) results indicate that the Pt coating can greatly reduces the non-radiative recombination rate by passivation of surface states, making the decay slow down. Temperature dependence of the integrated photoluminescence intensity reveals that the Pt nano-patterns can offer a large amount of light transfer and scattering, which enormously increase the light extraction efficiency up to 3.8-fold. These results indicate that the increased light extraction efficiency caused by surface modification via Pt coating rather than SP coupling plays a dominant role in increasing bandgap emission of MgZnO film.