Investigation of defects in indium doped TiO2 thin films using electrical and optical techniques

摘要: Abstract Existence of defect levels into the band gap titanium oxide (TiO2) due to indium (In) doping was investigated by Deep level transition spectroscopy (DLTS), Raman Spectroscopy and photoluminescence (PL). Particularly, two distinct e-beam grown TiO2 thin film (TF) samples on Si substrates were doped using In films with thicknesses 5 nm 50 nm instantaneous source. It observed that increasing in concentration has changed crystal structure from anatase rutile phase. addition, low Ti/Au/5 nm In/TiO2 TF showed at −5 V reverse-bias lower leakage current (3.0 × 10−7 A) as compared highly Ti/Au/50 nm devices (7.0 × 10−5 A). The free carrier increased about 1014 cm−3 1015 cm−3 for devices, respectively. DLTS results have revealed a unique behaviour where substantial reduction deep trap having larger doping. A PL around 2.4 eV 1.9 eV samples, respectively blue shift (PL) energy peak increase temperature also both associated related emissions. Finally, shallow activation determined dependence spectra. 25 meV In-doped 65 meV TFs.