Nanowire dye-sensitized solar cells.
Excitonic solar cells-including organic, hybrid organic-inorganic and dye-sensitized cells (DSCs)-are promising devices for inexpensive, large-scale solar energy conversion. The DSC is currently the most efficient and stable excitonic photocell. Central to this device is a thick nanoparticle film that provides a large surface area for the adsorption of light-harvesting molecules. However, nanoparticle DSCs rely on trap-limited diffusion for electron transport, a slow mechanism that can limit device efficiency, especially at longer wavelengths. Here we introduce a version of the dye-sensitized cell in which the traditional nanoparticle film is replaced by a dense array of oriented, crystalline ZnO nanowires. The nanowire anode is synthesized by mild aqueous chemistry and features a surface area up to one-fifth as large as a nanoparticle cell. The direct electrical pathways provided by the nanowires ensure the rapid collection of carriers generated throughout the device, and a full Sun efficiency of 1.5% is demonstrated, limited primarily by the surface area of the nanowire array.
Law
Matt
M
Department of Chemistry, University of California, Berkeley, California 94720, USA.
Greene
Lori E
LE
Johnson
Justin C
JC
Saykally
Richard
R
Yang
Peidong
P
D004396:Coloring Agents / Q000737:chemistry / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D011211:Electric Power Supplies; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008422:Materials Testing; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D043942:Nanotubes / Q000737:chemistry* / Q000528:radiation effects* / Q000648:ultrastructure; D011829:Radiation Dosage; D012993:Solar Energy; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects; D015034:Zinc Oxide / Q000737:chemistry* / Q000528:radiation effects
D004396:Coloring Agents; C009495:titanium dioxide; D014025:Titanium; D015034:Zinc Oxide