Research of high refractive index transparent conducting Nb-doped TiO2 (TNO) films and its application on high reflection mirror

• Main Authors: Ssu-hsiang Peng, 彭思翔
• Other Authors: Cheng-chung Lee
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/31656331611613588338

碩士 === 國立中央大學 === 光電科學研究所 === 98 === Transparent conducting oxide (TCO) is a special material. It has the characteristic that like metals it can conduct electricity. Furthermore metal oxides are transparent in the visible light region. Presently, TCO is a key component in solar cells, organic light emitting displays (OLEDs), light emitting displays (LEDs), flat panel displays (FPDs), touch panels, etc. Sn-doped In2O3 (ITO) is a major component of the most widely used TCO, because it has excellent resistivity and transmittance in the visible light region. However, indium is in short supply worldwide, which pushes up the cost. This motivates researchers to develop alternatives to ITO. Furubayashi et al. have recently published results on the development of an In-free TCO material, Nb-doped anatase TiO2 (TNO). The material has development of a novel transparent conductive oxide. In this study, we deposited the Nb-doped TiO2 films, and then investigated the electrical and optical characteristics of the films. We used the high refractive index of characteristic of TNO films with AZO to design and deposit transparent conducting oxide of high reflectance. The low resistivity Nb-doped TiO2 films, the number of atoms of titanium and niobium ratio was from 9 to 17, were deposited when the DC power for the Nb target was from 20 to 24 W, with resistivity of ~4.6×10-4 Ω-cm, mobility of ~1.15 cm2/V-s, and carrier concentrations of ~1.18×1022 cm-3. The films exhibited an average optical transmittance of ~72 % and absorbance <10 % in the visible region. The transparent conducting oxide of high reflectance was deposited by using TNO and AZO. The highest reflectance was 90 % at 550 nm and resistivity was 1.88×10-3 Ω-cm.