Transparent Conducting Films with Multi-layered Structure Prepared by Pulsed Laser Deposition of SnO2 Materials

Abstract

There are two advantageous points for fluorine-doped tin-oxide (FTO) films if used as transparent conducting electrodes; the one is high average transmittance in the wave length region between 400 nm and 1500 nm which is favorable for thin film solar cells and the second is to improve anti-heat or anti-humidity properties of Al-doped zinc oxide (AZO) films when employed as a laminated structure of FTO and AZO layers. Therefore, approximately 500 nm-thick multi-layer transparent conducting films (FTO film (100 nm-thick) as protection layer/AZO film (400 nm-thick)) have been prepared. FTO films and AZO films were deposited at substrate temperature of 420~500°C and 280°C, respectively. Sheet resistance of 6.7 Ω/□ was obtained for the structure of FTO layer (fabricated at oxygen partial pressure of 0.5 Pa) and AZO layer (fabricated at oxygen partial pressure of 0 Pa).