Da Qin

Dye-sensitized solar cells with NiS counter electrodes electrodeposited by a potential reversal technique

Nickel sulfides have been, for the first time, electrodeposited on transparent conductive glass by a facile periodic potential reversal (PR) technique to supersede Pt counter electrodes (CEs) of dye-sensitized solar cells (DSCs). The composition and electrochemical catalytic activity of the nickel sulfide films prepared by PR technique are different from those of the ones deposited by the commonly used potentiostatic (PS) technique. PR technique produces transparent single-component NiS, while co-deposition of Ni and NiS is found in the opaque films prepared by PS method. The nickel sulfide deposited by PR technique shows high catalytic activity for the reduction of I3− to I− in a DSC. DSC with the CE deposited by PR technique performs much better (6.82%) than that by PS method (3.22%), and is comparable to the device with conventional Pt coated CE (7.00%).

Optimization the solid-state electrolytes for dye-sensitized solar cells

The dye-sensitized solar cell (DSC) as a low price photovoltaic technology has attracted widespread attention in recent years. During its progress to practical application, replacement of the liquid electrolytes by solid-state ones has been found to be necessary. Alternative solid-state electrolytes have thus been developed. This review deals with the recent progress of different solid-state electrolytes on DSCs. In particular, representative examples are highlighted with the results of our solid-state composite electrolytes based on addition compounds.

Quasi-solid-state dye-sensitized solar cell fabricated with poly (β-hydroxyethyl methacrylate) based organogel electrolyte

A novel freestanding poly (β-hydroxyethyl methacrylate), PHEMA-based organogel electrolyte is developed simply by optimization of the solution polymerization in the same solvent as the organic electrolyte for dye-sensitized solar cells (DSCs). The room temperature ionic conductivity of the gel electrolyte is 4.54 × 10−3 S cm−1, and the conduction behavior can be well described by the free volume model. The quasi-solid-state dye-sensitized solar cell fabricated with this PHEMA-based polymer gel electrolyte can present high energy conversion efficiency up to 7.5%. Preliminary long-term stability test further reveals that this quasi-solid-state electrolyte exhibits good stability after 1000 h thermal test in comparison with the DSCs based on corresponding liquid electrolyte.

The potential of eutectic mixtures as environmentally friendly, solvent-free electrolytes for dye-sensitized solar cells

A new kind of solvent-free eutectic melt electrolytes for dye-sensitized solar cells (DSCs) has been designed, which are composed of imidazolium salts (i.e. 1-methyl-3-acetylimidazolium iodide (MAII), 1-ethyl-3-methylimidazolium iodide (EMII)) and plastic crystal succinonitrile (SN). Differential scanning calorimetric measurement reveals that the eutectic melt mixture EMII/SN can exhibit stable liquid state in the whole temperature domain from −80 to 80 °C. Besides, the conductivities of the eutectic melt electrolytes are higher than conventional imidazolium-based ionic liquid, 1-propyl-3-methylimidazolium iodide (PMII). Up to 7.46% of light-to-electricity conversion efficiency has been achieved by using the SN-based eutectic melt electrolyte, higher than PMII-based DSCs. Besides, the devices based on eutectic melt electrolytes exhibit good thermal stability. These results show that succinonitrile-based eutectic melts as environmentally friendly electrolytes, possess great potential for large-scale outdoor application of DSCs.

Low Cost, Environmentally Friendly, In Situ Prepared Quasi-Solid-State AlI3 Electrolyte for Dye-Sensitized Solar Cells

The magnetic properties of magnetosome magnetite are of interdisciplinary interest because magnetosomes are potential carriers of natural remanent magnetization and paleoenvironment, as well as novel nano-biomaterials in biotechnological and biomedical applications. We carried out magnetic and electron transmission microscopy analyses of fresh Magnetospirillum magneticum AMB-1 whole cells and isolated magnetosomes. Results revealed that AMB-1 synthesized single-domain magnetite magnetosomes, which are arranged in the form of linear fragmental chain. The distinct differences of magnetic properties between these two samples can be faithfully interpreted in terms of spatial arrangement of magnetosomes and magnetostatic interaction. For the whole cells, the strong intra-chain interactions and weak inter-chain interactions generate behaviors of non-interacting uniaxial single-domain particles. Its delta-ratio is 3.0 and passes the Moskowitz test. In contrast, the isolated magnetosome sample has reduced values of coercivity and delta-ratio (1.5), due to increasing three-dimensional magnetostatic interactions and collapse of magnetosome chains. These observations provide useful insights into applications of the biogenic magnetite (magnetosomes) in magnetic nano-materials and magnetofossils in the paleomagnetic and environmental magnetism.