scispace - formally typeset

Journal ArticleDOI

A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films

24 Oct 1991-Nature (Nature Publishing Group)-Vol. 353, Iss: 6346, pp 737-740

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 methods1. 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-µm-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.
Topics: Solar cell (58%), Polymer solar cell (56%), Photovoltaic system (56%), Dye-sensitized solar cell (56%), Solar energy (55%)
More filters

Journal ArticleDOI
Xiaobo Chen1, Samuel S. Mao1Institutions (1)
23 Jun 2007-Chemical Reviews

8,742 citations

Journal ArticleDOI
Anders Hagfeldt1, Gerrit Boschloo1, Licheng Sun1, Lars Kloo1  +1 moreInstitutions (1)
10 Sep 2010-Chemical Reviews
Abstract: Dye-sensitized solar cells (DSCs) offer the possibilities to design solar cells with a large flexibility in shape, color, and transparency. DSC research groups have been established around the worl ...

8,076 citations

Cites background from "A low-cost, high-efficiency solar c..."

  • ...At present, there is a considerable effort being devoted to DSSC with nanoporous photoanodes [9,56]....


  • ...[8,9]....


  • ...1% [9], comparable with the amorphous Si cells [11]....


Journal ArticleDOI
02 Nov 2012-Science
TL;DR: A low-cost, solution-processable solar cell, based on a highly crystalline perovskite absorber with intense visible to near-infrared absorptivity, that has a power conversion efficiency of 10.9% in a single-junction device under simulated full sunlight is reported.
Abstract: The energy costs associated with separating tightly bound excitons (photoinduced electron-hole pairs) and extracting free charges from highly disordered low-mobility networks represent fundamental losses for many low-cost photovoltaic technologies. We report a low-cost, solution-processable solar cell, based on a highly crystalline perovskite absorber with intense visible to near-infrared absorptivity, that has a power conversion efficiency of 10.9% in a single-junction device under simulated full sunlight. This "meso-superstructured solar cell" exhibits exceptionally few fundamental energy losses; it can generate open-circuit photovoltages of more than 1.1 volts, despite the relatively narrow absorber band gap of 1.55 electron volts. The functionality arises from the use of mesoporous alumina as an inert scaffold that structures the absorber and forces electrons to reside in and be transported through the perovskite.

7,996 citations

Journal ArticleDOI
18 Oct 2013-Science
Abstract: Organic-inorganic perovskites have shown promise as high-performance absorbers in solar cells, first as a coating on a mesoporous metal oxide scaffold and more recently as a solid layer in planar heterojunction architectures. Here, we report transient absorption and photoluminescence-quenching measurements to determine the electron-hole diffusion lengths, diffusion constants, and lifetimes in mixed halide (CH3NH3PbI(3-x)Cl(x)) and triiodide (CH3NH3PbI3) perovskite absorbers. We found that the diffusion lengths are greater than 1 micrometer in the mixed halide perovskite, which is an order of magnitude greater than the absorption depth. In contrast, the triiodide absorber has electron-hole diffusion lengths of ~100 nanometers. These results justify the high efficiency of planar heterojunction perovskite solar cells and identify a critical parameter to optimize for future perovskite absorber development.

6,875 citations

Journal ArticleDOI
Ulrike Diebold1Institutions (1)
Abstract: Titanium dioxide is the most investigated single-crystalline system in the surface science of metal oxides, and the literature on rutile (1 1 0), (1 0 0), (0 0 1), and anatase surfaces is reviewed This paper starts with a summary of the wide variety of technical fields where TiO 2 is of importance The bulk structure and bulk defects (as far as relevant to the surface properties) are briefly reviewed Rules to predict stable oxide surfaces are exemplified on rutile (1 1 0) The surface structure of rutile (1 1 0) is discussed in some detail Theoretically predicted and experimentally determined relaxations of surface geometries are compared, and defects (step edge orientations, point and line defects, impurities, surface manifestations of crystallographic shear planes—CSPs) are discussed, as well as the image contrast in scanning tunneling microscopy (STM) The controversy about the correct model for the (1×2) reconstruction appears to be settled Different surface preparation methods, such as reoxidation of reduced crystals, can cause a drastic effect on surface geometries and morphology, and recommendations for preparing different TiO 2 (1 1 0) surfaces are given The structure of the TiO 2 (1 0 0)-(1×1) surface is discussed and the proposed models for the (1×3) reconstruction are critically reviewed Very recent results on anatase (1 0 0) and (1 0 1) surfaces are included The electronic structure of stoichiometric TiO 2 surfaces is now well understood Surface defects can be detected with a variety of surface spectroscopies The vibrational structure is dominated by strong Fuchs–Kliewer phonons, and high-resolution electron energy loss spectra often need to be deconvoluted in order to render useful information about adsorbed molecules The growth of metals (Li, Na, K, Cs, Ca, Al, Ti, V, Nb, Cr, Mo, Mn, Fe, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au) as well as some metal oxides on TiO 2 is reviewed The tendency to ‘wet’ the overlayer, the growth morphology, the epitaxial relationship, and the strength of the interfacial oxidation/reduction reaction all follow clear trends across the periodic table, with the reactivity of the overlayer metal towards oxygen being the most decisive factor Alkali atoms form ordered superstructures at low coverages Recent progress in understanding the surface structure of metals in the ‘strong-metal support interaction’ (SMSI) state is summarized Literature is reviewed on the adsorption and reaction of a wide variety of inorganic molecules (H 2 , O 2 , H 2 O, CO, CO 2 , N 2 , NH 3 , NO x , sulfur- and halogen-containing molecules, rare gases) as well as organic molecules (carboxylic acids, alcohols, aldehydes and ketones, alkynes, pyridine and its derivates, silanes, methyl halides) The application of TiO 2 -based systems in photo-active devices is discussed, and the results on UHV-based photocatalytic studies are summarized The review ends with a brief conclusion and outlook of TiO 2 -based surface science for the future

6,656 citations

More filters

Journal ArticleDOI
Akira Fujishima1, Kenichi Honda2Institutions (2)
07 Jul 1972-Nature
TL;DR: Water photolysis is investigated by exploiting the fact that water is transparent to visible light and cannot be decomposed directly, but only by radiation with wavelengths shorter than 190 nm.
Abstract: ALTHOUGH the possibility of water photolysis has been investigated by many workers, a useful method has only now been developed. Because water is transparent to visible light it cannot be decomposed directly, but only by radiation with wavelengths shorter than 190 nm (ref. 1).

24,267 citations

Journal ArticleDOI
Abstract: Transparent titanium dioxide membranes (thickness 2.7 {mu}m) were prepared by sintering of 8-nm colloidal anatase particles on a conducting glass support. The dynamics of charge recombination following electron injection from the excited state of RuL{sub 3} (L = 2,2{prime}-bipyridine-4,4{prime}-dicarboxylic acid) into the conduction band of the semiconductor were examined under potentiostatic control of the electric field within the space charge layer of the membrane. Biasing the Fermi level of the TiO{sub 2} positive of the flat-band potential sharply reduced the recombination rate, a 1,000-fold decrease being associated with a potential change of only 300 mV. Photoelectrochemical experiments performed with the same RuL{sub 3}-loaded membrane in NaI-containing water show the onset of anodic photocurrent to occur in the same potential domain. Forward biasing of the membrane potential impairs photosensitized charge injection turning on the photoluminescence of the adsorbed sensitizer.

688 citations

Journal ArticleDOI
Heinz Gerischer1Institutions (1)
Abstract: The study and kinetic interpretation of electrode reactions was, from the early years of electrochemistry, dominated by processes occurring at electrodes with metallic conductivity Only since the late 1950s and early 1960s has it been realized that semiconductor electrodes behave differently in many respects and offer new insights into the role played by the electronic properties of a solid in its electrochemical reactivity The investigation of semiconductor electrodes has intensified the link between electrochemistry and solid state physics, has created a close connection to photochemistry and has profoundly improved the understanding of interfacial reactions Selected examples are presented in this lecture

374 citations

Journal ArticleDOI
Abstract: The chemical and photochemical behaviour of MoS 2 -van der Waals surfaces in contact with an aqueous electrolyte has been investigated by means of electrochemical techniques. The covalent bonding character of this layer crystal and a molybdenum d z 2-band which is split off from the 4d molybdenum conduction band and overlaps the sulfur 3p valence band give rise to reaction behaviour which is very different from that found with polar metal-sulfide compounds: sulfate and not molecular sulfur is the main product of the electrochemical and photochemical oxidation of MoS 2 which occurs as p − , n − , or intrinsic semiconductor material. A parallel photochemical liberation of molecular oxygen could be traced on freshly prepared surfaces by means of polarographic techniques. The quantum efficiency for the photoelectrochemical reaction with water in the visible spectral range approaches 100% if a positive electrode potential of 2 V is applied. Several electron-transfer reactions were examined and the interrelation between d-band structure of the layer sulfide and some of its electrochemical behaviour is discussed.

324 citations

No. of citations received by the Paper in previous years