Abstract: Sol-gel thin films prepared by rotating coating technique, sol–gel derived bulk was prepared from constant water (H2O)/tetraethyl-orthosilicate (TEOS) ratio, rotating coating was carried out at different rotating speed 1000r/min (high speed) and 800r/min (low speed), 1500r/min (high speed) and 800r/min (low speed),2000r/min (high speed) and 800r/min (low speed),2500r/min (high speed) and 800r/min (low speed) respectively. The films were characterized by ellipsometer and SEM respectively. The experimental results show the thickness and refractive index of films are become smaller and smaller with the rotating speeds increasing.
Abstract: High quality textured ZnO:Al electrode can improve the energy conversion efficiency of silicon based thin film solar cells. Two groups of ZnO:Al films were fabricated under different sputtering powers. Different textured surfaces were got when corroding ZnO:Al films with diluted HCl solutions of different concentration. The transmission spectrum and square resistance of the samples were measured. The dependence of sputtering power and corrosion time on the resistivity, transmittance and surface texture of the samples were studied. The results showed that the density of the ZnO:Al film was mainly affected by sputtering power. The compactness of the film increases with the increase of sputtering power. The corrosion rates of the samples with different compactness follow different rules. High quality textured ZnO:Al electrode was obtained when the ZnO:Al film deposited under sputtering power of 200W was corroded by diluted HCl solution of 0.5%.
Abstract: Eu3+ or/and Sm3+ co-doped glasses based on TeO2-ZnO-ZnCl2-Li2O are prepared using the melt quenching technique and the effects of co-doping on the emission spectra of these glasses are examined. The Sm3+ doped glass under 403 nm excitations show emission bands around 561, 598 and 642 nm corresponding to the transitions of 4G5/2 →6H5/2, 4G5/2→6H7/2 and 4G5/2→6H9/2 respectively. Whereas, in Eu3+ doped glass under 397 nm excitation emission bands appear around 553, 586, 613, 650 and 699 nm that corresponds to the transitions of 5D1→7F2, 5D0 →7F1, 5D0 →7F2, 5D0→7F3 and 5D0→7F4. In addition, the emission spectra of the Eu3+/Sm3+ co-doped glass under 482 nm excitation consists of five bands in which three are contributed by Sm3+ at 561, 598 and 642 nm and two by Eu3+ at 613 nm and 699 nm respectively. Surprisingly, the emission bands of Eu3+ are still observed in the emission spectra of Sm3+ for the Eu3+/Sm3+ co-doped glasses despite the absence of the excitation wavelength 482 nm in the absorption and excitation domain of Eu3+. This observation is attributed to the partial resonance transfer of the absorption energy from Sm3+ to the Eu3+ ions.