Preparation and Physical Properties of Zn-Sn-O Transparent Conductive Films

• Main Authors: Hau-Wei Fang, 方皓葦
• Other Authors: Yan-Ru Lin
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/87387201981112032238

碩士 === 明志科技大學 === 化工與材料工程研究所 === 97 === Transparent and conducting zinc tin oxide (Zn-Sn-O) films were grown on sapphire and LaAlO3 substrates at various temperatures and oxygen pressures by using pulsed-laser deposition technique with Zn-Sn-O targets of various Zn/Sn ratio. The effects of growth conditions on the material and physical properties of the fabricated films have been studied. A lowest resistivity of 6.3x10-3 Ω-cm and an average visible-range transmittance above 85% were obtained for Zn/Sn=1/1 films grown at 500C in oxygen pressure of 10-2 torr. Zn evaporation was observed in the Zn-Sn-O films grown or annealed at high temperature (above 600C) and low oxygen pressure (below 10-1 torr), and SnO2 crystalline films were obtained at temperatures above 750℃. Moreover, Zn evaporation was observed in both films grown on LaAlO3 and sapphire substrates. It indicates that Zn evaporation is not resulted from the lattice mismatch between Zn-Sn-O films and substrates. On the other hand, the roughness of films is decreased with increasing the growth temperature. The optical bandgaps of Zn-Sn-O films increase with increasing the growth temperatures and Zn contents. A second absorption at short wavelength (~360nm) which could be resulted from co-exist of crystalline and amorphous phases was observed in films grown at room temperature and then post-annealed at high temperatures. The resistivity of Zn-Sn-O films can be reduced by increasing the growth temperatures and by decreasing Zn and O contents. Zn evaporation was not observed in the films which were post-annealed in air even though the annealing temperature was as high as 800℃. Furthermore, Zn evaporation was not observed in the crystalline Zn2SnO4 films annealed at a high temperature of 750C in a vacuum of 10-6 torr.