Homogeneous photosensitization of complex TiO₂ nanostructures for efficient solar energy conversion.
TiO₂ nanostructures-based photoelectrochemical (PEC) cells are under worldwide attentions as the method to generate clean energy. For these devices, narrow-bandgap semiconductor photosensitizers such as CdS and CdSe are commonly used to couple with TiO₂ in order to harvest the visible sunlight and to enhance the conversion efficiency. Conventional methods for depositing the photosensitizers on TiO₂ such as dip coating, electrochemical deposition and chemical-vapor-deposition suffer from poor control in thickness and uniformity, and correspond to low photocurrent levels. Here we demonstrate a new method based on atomic layer deposition and ion exchange reaction (ALDIER) to achieve a highly controllable and homogeneous coating of sensitizer particles on arbitrary TiO₂ substrates. PEC tests made to CdSe-sensitized TiO₂ inverse opal photoanodes result in a drastically improved photocurrent level, up to ~15.7 mA/cm² at zero bias (vs Ag/AgCl), more than double that by conventional techniques such as successive ionic layer adsorption and reaction.
Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore.
Jingshan
J
Luo
Siva Krishna
SK
Karuturi
Lijun
L
Liu
Liap Tat
LT
Su
Alfred Iing Yoong
AI
Tok
Hong Jin
HJ
Fan
D003246:Conservation of Energy Resources / Q000379:methods*; D004563:Electrochemistry / Q000379:methods; D008854:Microscopy, Electron; D008956:Models, Chemical; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure; D055668:Photochemical Processes / Q000528:radiation effects; D010777:Photochemistry / Q000379:methods; D012993:Solar Energy; D013472:Sunlight; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000737:chemistry
C009495:titanium dioxide; D014025:Titanium; D015034:Zinc Oxide