The structure and photoelectrochemistry of Al, Ti Co-doped zinc oxide thin films prepared by sol-gel dip-coating process

Al, Ti co-doped ZnO (ATZO) thin films were prepared on glass substrate via sol-gel dip-coating process. Importantly, we replaced the toxic 2-methoxy-ethanol by nontoxic ethanol as a much safer reagent. The dip-coating was repeated four times and as-obtained thin films were then annealed at 500 °C for 1 h in air. We found that introducing Al and Ti dopant would transfer the principal diffraction peak from (101) to (002), decrease the vibration strength of E2 high and E1 LO, lead a relative smoother surface, blueshift the band gap, decrease resistance and increase photocurrent density. Also, doping Al and Ti arose the open circuit potential and as a result, increased the anticorrection of ATZO films.