COLL 495 |
| Hierachically-structured ZnO nanoparticle films consisting of secondary colloidal spheres of 150-400 nm in diameter with primary nanoparticles of 15-18 nm in diameter were synthesized and used as electrode in dye-sensitized solar cells. The overall conversion efficiency for such hierarchically-structured ZnO DSSC was up to 5.4 % with an open-circuit voltage of ~ 670 mV, a short-circuit current density of ~ 18 mA/cm2, and a fill factor of ~ 48%. The overall light conversion efficiency has been increased more than 100% compared to conventional ZnO nanoparticle DSSC. Such significant enhancement in ZnO DSSC performance is attributed to improved photon absorption resulting from extended traveling distance of light due to light scattering on the surface of submicron aggregates of ZnO nanocrystallites. ZnO nanocrystallites offer desired high surface area of ~ 80 m2/g to adsorb a sufficient amount of dye molecules for photon capturing. |
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Interfacial Electron Transfer and Solar Energy Conversion: From Molecules to Nanomaterials
2:00 PM-5:00 PM, Thursday, April 10, 2008 Morial Convention Center -- Rm. 226, Oral
Division of Colloid & Surface Chemistry |