Abstract
•The best crystallographic properties obtained on samples grown on (311)B planes.•Electrical properties of samples grown on (311)B have been enhanced by indium doping.•A red-shift makes sample 15 (311)B more suitable material for solar cells.
The properties of In-doped TiO2 grown by Pulsed Laser Deposition on (100) and (311)B GaAs substrates have been investigated. X-ray diffraction and photoluminescence results have shown that samples grown on (311)B GaAs planes have better crystallographic properties than those grown on (100). Both anatase and rutile phases were detected in samples with lower In-doping (In = 5 nm) while only rutile phase was observed for higher In-doped samples (In = 15 nm). Furthermore, In-doping adversely affected the electrical properties of samples grown on (100) substrates while it enhanced those of (311)B samples. Two shallow defects were detected in all samples except for (311)B sample (In = 15 nm) where three shallow defects were observed. The presence of more shallow defects in this sample is evidenced by a red-shift in the absorption spectrum. It was concluded that sample (311)B (In = 15 nm) is best among all other samples and makes it more suitable for solar cell applications.