title: N-Ion-implanted TiO2 photoanodes in quantum dot-sensitized solar cells.
abstract: Hierarchical nanostructured titanium dioxide (TiO(2)) clumps were fabricated using electrostatic spray with subsequent nitrogen-ion doping by an ion-implantation technique for improvement of energy conversion efficiency for quantum dot-sensitized solar cells (QDSCs). CdSe quantum dots were directly assembled on the produced N-ion-implanted TiO(2) photoanodes by chemical bath deposition, and their photovoltaic performance was evaluated in a polysulfide electrolyte with a Pt counter electrode. We found that the photovoltaic performance of TiO(2) electrodes was improved by nearly 145% upon N-ion implantation. The efficiency improvement seems to be due to (1) the enhancement of electron transport through the TiO(2) layer by inter-particle necking of primary TiO(2) particles and (2) an increase in the recombination resistance at TiO(2)/QD/electrolyte interfaces by healing the surface states or managing the oxygen vacancies upon N-ion doping. Therefore, N-ion-doped photoanodes offer a viable pathway to develop more efficient QD or dye-sensitized solar cells.
authors.affiliation: WCU Program Department of Energy Engineering and Center for Next Generation Dye-sensitized Solar Cells, Hanyang University, Seoul 133791, South Korea.
authors.forename: P
authors.initials: P
authors.lastname: Sudhagar
authors.forename: K
authors.initials: K
authors.lastname: Asokan
authors.forename: E
authors.initials: E
authors.lastname: Ito
authors.forename: Yong Soo
authors.initials: YS
authors.lastname: Kang
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation; D011232:Chemical Precipitation; D011211:Electric Power Supplies; D004566:Electrodes; D007477:Ions / Q000737:chemistry; D008954:Models, Biological; D009584:Nitrogen / Q000737:chemistry*; D010316:Particle Size; D010777:Photochemistry; D045663:Quantum Dots; D012993:Solar Energy; D055672:Static Electricity; D013472:Sunlight; D014025:Titanium / Q000737:chemistry*
chemical_list: D007477:Ions; C009495:titanium dioxide; D014025:Titanium; D009584:Nitrogen