Three-dimensional (3D) perovskite materials display remarkable potential in photovoltaics owing to their superior solar-to-electric power conversion efficiency, with current efforts focused on improving stability. Two-dimensional (2D) perovskite analogues feature greater stability toward environmental factors, such as moisture, owing to a hydrophobic organic cation that acts as a spacer between the inorganic layers, which offers a significant advantage over their comparatively less stable 3D analogues. Here, we demonstrate the first example of a formamidinium (FA) containing Dion-Jacobson 2D perovskite material characterized by the BFA Pb I formulation through employing a novel bifunctional organic spacer (B), namely 1,4-phenylenedimethanammonium (PDMA).
View Article and Find Full Text PDFWe investigate two different types of TiO2 blocking layer (BL) deposition techniques commonly used in solid-state methylammonium lead triiodide perovskite (MaPbI3)-based solar cells. Although these BLs lead to similar photovoltaic device performance, their structure and blocking capability is actually very different. In one case, the "blocking" layer is porous, allowing an intimate contact of the perovskite with the fluorine-doped tin-dioxide (FTO)-covered glass substrate serving as transparent electron collector.
View Article and Find Full Text PDFOrganolead iodide perovskite, CH3NH3PbI3, was prepared in the form of nanowire by means of a small quantity of aprotic solvent in two-step spin-coating procedure. One-dimensional nanowire perovskite with the mean diameter of 100 nm showed faster carrier separation in the presence of hole transporting layer and higher lateral conductivity than the three-dimensional nanocuboid crystal. Reduction in dimensionality resulted in the hypsochromic shift of both absorption and fluorescence spectra, indicative of more localized exciton states in nanowires.
View Article and Find Full Text PDFAlthough sunlight-driven water splitting is a promising route to sustainable hydrogen fuel production, widespread implementation is hampered by the expense of the necessary photovoltaic and photoelectrochemical apparatus. Here, we describe a highly efficient and low-cost water-splitting cell combining a state-of-the-art solution-processed perovskite tandem solar cell and a bifunctional Earth-abundant catalyst. The catalyst electrode, a NiFe layered double hydroxide, exhibits high activity toward both the oxygen and hydrogen evolution reactions in alkaline electrolyte.
View Article and Find Full Text PDFPerovskite solar cells with submicrometre-thick CH(3)NH(3)PbI(3) or CH(3)NH(3)PbI(3-x)Cl(x) active layers show a power conversion efficiency as high as 15%. However, compared to the best-performing device, the average efficiency was as low as 12%, with a large standard deviation (s.d.
View Article and Find Full Text PDFTiO2 nanoparticle (NP)/ITO nanowire (NW) nanocomposites for use as photoelectrode materials were fabricated to improve the charge collection efficiency in solid state dye sensitized solar cells (ss-DSSCs). The average current density for ss-DSSCs containing TiO2 NP/ITO NW arrays was 7.2 mA cm(-2) that was 98% higher than that for the conventional TiO2 NP ss-DSSCs.
View Article and Find Full Text PDFWe report on solid-state mesoscopic heterojunction solar cells employing nanoparticles (NPs) of methyl ammonium lead iodide (CH(3)NH(3))PbI(3) as light harvesters. The perovskite NPs were produced by reaction of methylammonium iodide with PbI(2) and deposited onto a submicron-thick mesoscopic TiO(2) film, whose pores were infiltrated with the hole-conductor spiro-MeOTAD. Illumination with standard AM-1.
View Article and Find Full Text PDFSize-tunable titanium oxide (TiO(2)) nanotube powders offering both a light-scattering effect and a light-harvesting function were synthesized by a fast and facile anodizing method. When used to prepare the TiO(2) layer for a photoanode, their photovoltaic performances were much worse than that of a nanocrystal TiO(2) layer. However, when the TiO(2) nanotube powders were used as a light-scattering layer on a nanocrystal TiO(2) layer, the highest conversion efficiency was obtained because of more noticeable light absorption of the longer wavelength, which was not attainable from a pure nanocrystal TiO(2) layer or the combination of nanocrystal TiO(2)/commercialized light-scattering particles.
View Article and Find Full Text PDFA new nanocrystalline sensitizer with the chemical formula (CH3CH2NH3)PbI3 is synthesized by reacting ethylammonium iodide with lead iodide, and its crystal structure and photovoltaic property are investigated. X-ray diffraction analysis confirms orthorhombic crystal phase with a = 8.7419(2) Å, b = 8.
View Article and Find Full Text PDFHighly efficient quantum-dot-sensitized solar cell is fabricated using ca. 2-3 nm sized perovskite (CH(3)NH(3))PbI(3) nanocrystal. Spin-coating of the equimolar mixture of CH(3)NH(3)I and PbI(2) in γ-butyrolactone solution (perovskite precursor solution) leads to (CH(3)NH(3))PbI(3) quantum dots (QDs) on nanocrystalline TiO(2) surface.
View Article and Find Full Text PDFACS Appl Mater Interfaces
June 2011
We have investigated the adsorption kinetics of Ru-based N719 dye on TiO(2) surface in dye-sensitized solar cell using 0.5 mM and 5 mM dye solutions. The amount of adsorbed dye on TiO(2) surface of ca.
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