Effect of Co2+ doping on photoelectric properties of ZnO crystal planes

•ZnO nanoparticles were successfully synthesized by chemical precipitation method and doped on the surface of Co2+.•The effects of Co2+ doping on the characteristic adsorption species and optoelectronic properties of the ZnO crystal surface have been simulated by density functional theory (DFT).•The simulated data show the characteristic adsorption species of crystal plane changed before and after doping with Co2+.•The conductivity is proportional to the coverage rate before doping with Co2+, The conductivity is inversely proportional to the coverage rate after doping with Co2+.•The photocurrent spectrum fitting data is consistent with the regular of experimental data, indicating that the chemical adsorption of characteristic adsorbed O2 and the conductivity of materials can be regulated by crystal plane Co2+ doping. The effects of Co2+ doping on the characteristic adsorption species and optoelectronic properties of the ZnO crystal plane have been simulated by Density Functional Theory (DFT). Because of the linear relationship between the Fermi level density of states and the conductivity, the conductivity is reacted by the Fermi level density of states. The simulated data show the characteristic adsorption species of crystal plane changed before and after doping with Co2+: The characteristic chemisorption species (CCS) O2 molecules disappear after the ZnO (002) plane is doped with Co2+, CCS O2 molecules appear after (200) plane is doped with Co2+, CCS H2O molecules appear after (110) plane is doped with Co2+. The conductivity decreases after doping with three crystal planes. The CCS of O2 molecules has a significant effect on the conductivity. The CCS of H2O molecules has no obvious effect on the conductivity. The effect of O2 molecular coverage rate of CCS on conductivity: The conductivity is proportional to the coverage rate of CCS before doping with Co2+, the conductivity is inversely proportional to the coverage rate of CCS after doping with Co2+. The photocurrent spectrum fitting data is consistent with the regular of experimental data, indicating that the chemical adsorption of characteristic adsorbed O2 and the conductivity of materials can be regulated by crystal plane Co2+ doping, which plays a guiding role in regulating and making use of the characteristic O2 absorption properties of the material plane.