Novel Bi2O3-ZnO solid solutions as photoanode in DSSC

Zinc oxide has been well explored semiconductor material owing to superior properties like direct bandgap as well as large exciton binding energy of 60 meV. Variety of applications of zinc oxides has been reported like DSSC, photocatalysis, varistors, PEC etc. The optical bandgap of zinc oxide is 3.20 eV and that of bismuth oxide is 2.5-3.1 eV, the bandgap tuning of the solid solutions was achieved by doping zinc oxide with bismuth ions. A systematic study of synthesis and characterization of novel Bi2O3−ZnO solid solutions in various concentrations has been conducted. Various compositions of BixZn1-xOy have been synthesized using citrate nitrate gel combustion technique. The extent of doping in the formed metal oxide has been determined using ICP-AES analysis and the crystallinity and phase was examined using XRD revealing the formation of solid solution. The carrier density of donor states and conductivity of BixZn1-xOy were determined using Hall measurements. The doped metal oxides were analyzed as photoanode material in dye sensitized solar cells sensitized with N719 dye using IV measurements. Maximum efficiency was obtained for Bi0.02Zn0.98Oy sample.