We present a time-saving staining protocol based upon the low-toxicity and nonvolatile solvent dimethyl sulfoxide for a high-efficiency dye-sensitized solar cell, which is very critical for the roll-to-roll flexible cell production. Power conversion efficiencies of 11.7-12.1% were achieved under AM1.5G simulated sunlights. The intrinsic roles of lithium cations on efficiency enhancement were scrutinized by measuring transient absorption and electrical impedance spectroscopies. Our studies have revealed that lithium ions can enhance exciton dissociation at the energy-offset dye/titania interface effectively. Charge collection is not found to be a crucial current loss channel in our high-efficiency dye-sensitized solar cell.

An N-annulated indenoperylene electron-donor decorated with photochemically inactive segments is synthesized and further conjugated via triple bond with electron-acceptor benzothiadiazolylbenzoic acid for a metal-free donor/acceptor dye. Without use of any coadsorbate, the judiciously tailored indenoperylene dye achieves a high-power conversion efficiency of 12.5% under irradiance of 100 mW cm(-2) AM1.5G sunlight.

High performance BiSbTe alloy and modules with a conversion efficiency of 5% are achieved through integrating Zn induced defect complexity with nanostructuring.

No abstract

With a new metal-free donorÀacceptor photosensitizer featuring the 2,6-bis(thiophen-2-yl)-4,4-dihexyl-4H-cyclopenta [2,1-b:3,4-b 0 ]dithiophene-conjugated spacer and the tris(1,10-phenanthroline)cobalt(II/III) redox shuttle, we present a highly efficient iodine-free dyesensitized solar cell displaying a power conversion efficiency of 9.4% measured at 100 mW cm À2 simulated AM1.5 conditions. D ye-sensitized solar cells (DSCs) are presently under intense academic and industrial investigations because of their grand potential to serve as a low-cost alternative to existing photovoltaic technologies.1 A state-of-the art DSC fabricated by sensibly combining a panchromatic ruthenium dye, 2 an iodine electrolyte, and a thick mesoporous titania film has been notarized with a record solar-to-electricity conversion efficiency of 11.1% thus far.3 Owing to a resource restriction of the noble metal ruthenium, metal-free organic pushÀpull dyes have been actively pursued for the wide availability of their raw materials. 4 In this context, impressive progress on iodine-free DSCs displaying an excellent photovoltage has been attained very recently, based upon the combination of high-absorptivity organic dyes with either a solid organic hole-transporter 5 or some iron-, 6 cobalt-, 7 and copper-containing 8 redox shuttles, all of which feature considerably downward-shifted Fermi levels with respect to the common iodine electrolytes. However, these explorations have not yet afforded power conversion efficiencies comparable to those of champion DSCs based on organic dyes and iodine electrolytes.4dÀf In this work, we employ 2,6-bis(thiophen-2-yl)-4,4-dihexyl-4H-cyclopenta[2,1-b:3,4-b 0 ]dithiophene as the π-conjugated linker to synthesize a new dye, coded C229 ( Figure 1A), which exhibits outstanding efficiencies of 9.4À 10.3% in DSCs based on the tris(1,10-phenanthroline)cobalt electrolyte.In comparison with the C228 dye ( Figure 1A) possessing the 2,7-bis(thiophen-2-yl)-9,9-dihexylfluorene segment, C229 takes on an augmented maximum molar absorption coefficient at a desirable longer wavelength (as shown in Supporting Information (SI), Figure S1), owing to a better electron delocalizability of its π-conjugated spacer. 9 We further examined the photocurrent action spectra ( Figure 1B À2 simulated AM1.5 conditions. A (2.7+4.1)-μm-thick bilayer titania film was employed for cell fabrication. An antireflection film was adhered to a testing cell during measurement. All cells were measured with a metal mask having an aperture area of 0.158 cm 2 . The spectral distribution of our light resource simulates the AM1.5 solar emission (ASTM G173-03). The validity of our data is further confirmed by comparing the overlap integral of the measured IPCE spectrum with the standard AM1.5 solar emission spectrum and the experimental J sc , showing <5% error.

Based upon the bis(2,9-dimethyl-1,10-phenanthroline)copper(I/II) electron mediator, we present an iodine-free dye-sensitized solar cell exhibiting an impressive power conversion efficiency of 7.0% at 100 mW cm(-2) air mass global (AM1.5G) conditions, which rivals that of a control cell with a conventional iodine redox couple.

No abstract

Plasmid DNA molecules with unique loop structures have widespread bioapplications, in many cases relying heavily on delivery vehicles to introduce them into cells and achieve their functions. Herein, we demonstrate that control over delicate nanotopography of silica nanoparticles as plasmid DNA vectors has significant impact on the transfection efficacy. For silica nanoparticles with rambutan-, raspberry-, and flower-like morphologies composed of spike-, hemisphere-, and bowl-type subunit nanotopographies, respectively, the rambutan-like nanoparticles with spiky surfaces demonstrate the highest plasmid DNA binding capability and transfection efficacy of 88%, higher than those reported for silica-based nanovectors. Moreover, it is shown that the surface spikes of rambutan nanoparticles provide a continuous open space to bind DNA chains via multivalent interactions and protect the gene molecules sheltered in the spiky layer against nuclease degradation, exhibiting no significant transfection decay. This unique protection feature is in great contrast to a commercial transfection agent with similar transfection performance but poor protection capability against enzymatic cleavage. Our study provides new understandings in the rational design of nonviral vectors for efficient gene delivery.