Article 5 of 11

Explanation

Document type: Article

Language: English

Cited References: 19

Times Cited: 891

Abstract:
THE large-scale use of photovoltaic devices for electricity generation is prohibitively expensive at present: generation from existing commercial devices costs about ten times more than conventional methods 1. Here we describe a photovoltaic cell, created from low-to medium-purity materials through low-cost processes, which exhibits a commercially realistic energy-conversion efficiency. The device is based on a 10-mu-m-thick, optically transparent film of titanium dioxide particles a few nanometres in size, coated with a monolayer of a charge-transfer dye to sensitize the film for light harvesting. Because of the high surface area of the semiconductor film and the ideal spectral characteristics of the dye, the device harvests a high proportion of the incident solar energy flux (46%) and shows exceptionally high efficiencies for the conversion of incident photons to electrical current (more than 80%). The overall light-to-electric energy conversion yield is 7.1-7.9% in simulated solar light and 12% in diffuse daylight. The large current densities (greater than 12 mA cm-2) and exceptional stability (sustaining at least five million turnovers without decomposition), as well as the low cost, make practical applications feasible.

KeyWords Plus:
PHOTOELECTROCHEMICAL CONVERSION, ELECTROCHEMISTRY, COMPLEXES, LIGHT, PHOTOCHEMISTRY, ELECTRICITY, ELECTRODES

Addresses:
SWISS FED INST TECHNOL,INST PHYS CHEM,CH-1015 LAUSANNE,SWITZERLAND

Publisher:
MACMILLAN MAGAZINES LTD, LONDON

IDS Number:
GL696

ISSN:
0028-0836