Solid State Phenomena Vols. 181-182

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 ⁴G_5/2 →⁶H_5/2, ⁴G_5/2→⁶H_7/2 and ⁴G_5/2→⁶H_9/2 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.