Recent progress in perovskite solar cells:material science

Perovskite solar cells represent a promising third-generation photovoltaic technology with low fabrication cost and high power conversion efficiency.In light of the rapid development of perovskite materials and devices,a systematic survey on the latest advancements covering a broad range of related work is urgently needed.This review summarizes the recent major advances in the research of perovskite solar cells from a material science perspective.The discussed topics include the devices based on different type of perovskites(organic-inorganic hybrid,all-inorganic,and lead-free perovskite and perovskite quantum dots),the properties of perovskite defects,different type of charge transport materials(organic,polymeric,and inorganic hole transport materials and inorganic and organic electron transport materials),counter electrodes,and interfacial materials used to improve the efficiency and stability of devices.Most discussions focus on the key progresses reported within the recent five years.Meanwhile,the major issues limiting the production of perovskite solar cells and the prospects for the future development of related materials are discussed.

低成本、高性能钙钛矿电池有机小分子空穴传输材料

钙钛矿太阳能电池由于其高能量转换效率(最高报道认证效率为25.2%)、低成本和易于制造等特点,成为下一代光伏技术的关注焦点.虽然钙钛矿材料本身可以传导空穴,但其效率比较低.空穴传输材料的使用成为有效提取电荷和提高钙钛矿型太阳能电池效率的关键因素.总结了近期报道的低成本、高性能有机小分子空穴传输材料(效率大于19%),从螺环结构、噻吩衍生物以及其它结构进行介绍,并从合成策略和化学修饰等角度评估结构-性能的构效关系及其对器件效率和稳定性的影响,最后对有机小分子空穴传输材料的发展趋势进行了展望.

双重发射过渡金属配合物与比率发光探针

双重发射过渡金属配合物可以同时展现出两个最大发射波长,它结合了双重发射与过渡金属配合物发光材料的双重优势,在待测物的分析检测与成像领域具有重要的研究价值与应用前景.相较于单重发射金属配合物,基于双重发射金属配合物的比率发光探针,可以有效减少环境的干扰并显著提高分析检测的灵敏度和准确性.本文简述了双重发射金属配合物(主要包括钌、铂、铱等配合物)的设计策略及其在分子氧、金属离子和生物大分子的比率发光检测方面的应用,并阐述了双重发射金属配合物的研究现状和存在的问题,为今后双重发射金属配合物的合成和应用提供参考与借鉴.

Electropolymerized films of redox-active ruthenium complexes for multistate near-infrared electrochromism,ion sensing,and information storage

This paper summarizes our recent progress on the preparations and applications of electropolymerized thin films of redox-active ruthenium complexes.Thin films of vinyl-functionalized diruthenium or ruthenium-amine conjugated complexes are prepared by reductive electropolymerization.The resulting films are useful for multistate near-infrared electrochromism,ion sensing,and mimicking flip-flop and flip-flap-flop logic gates.The oxidative electropolymerization of diruthenium complexes with two distal triarylamine units affords electropolymers with an alternating diruthenium and tetraphenylbenzidine structural unit.The applications of the resulting films in multistate near-infrared electrochromism and resistive memory are discussed.

A Star-Shaped Solvatofluorochromic Pyrene-Triarylamine Derivative as a Fluorescent Thermometer over a Wide Temperature Range

of main observation and conclusion A star-shaped compound 1 with a pyrene core and four triarylamine arms has been prepared and characterized.It exhibits intense intramolecular-charge-transfer(ICT)emissions with strong solvatofluorochromism.On the basis of the temperature-dependent emission color and wavelength changes,compound 1 behaves as a fluorescent thermometer between 200 and 400 Kwith a high theromosensitivity.In comparison,model compounds with one or two triarylamine arms show distinctly lower thermosensitivity.

Triarylamines with branched multi-pyridine groups： modulation of emission properties by structural variation, solvents,and tris(pentafluorophenyl)borane

Six triarylamine derivatives 1–6 with branched multi-pyridine substituents were prepared and characterized. These compounds are distinguished by the substituent on one of the phenyl group with NO2 for 1, CN for 2, Cl for 3, p-C6 H4 OMe for 4, OMe for 5,and NMe2 for 6, respectively. As revealed by single crystal X-ray analysis, these substituents play an important role in determining the configuration of the triarylamine framework and the crystal packing of 1–6. The emission properties of these compounds were examined in different solvents(toluene, CH2 Cl2, acetone, tetrahydrofuran(THF), and N,N-dimethylformamide(DMF)) and in solid states. Distinct dual emissions from the localized emissive state and the intramolecular charge transfer state were observed for compound 5 in CH2 Cl2. Compounds 1 and 6 show apparent aggregated enhanced emissions in acetone/H2 O.The emission properties of these compounds were further modulated by the addition of tris(pentafluorophenyl)borane. In addition, density functional theory(DFT) and time-dependent DFT(TDDFT) calculations have been performed on the ground and singlet excited states to complement the experimental findings.

Redox-responsive carbometalated ruthenium and osmium complexes

Organometallic conjugated complexes have become an important type of stimuli-responsive materials because of their appealing electrochemical properties and rich photonic, electronic, and magnetic properties. They are potentially useful in a wide range of applications such as molecular wires, molecular switches, molecular machines, molecular memory, and optoelectronic detections. This review outlines the recent progress on the molecular design of carbometalated ruthenium and osmium complexes and their applications as redox-responsive materials with visible and near-infrared(NIR) absorptions and electron paramagnetic resonance as readout signals. Three molecule systems are introduced, including the symmetric diruthenium complexes, metal-amine conjugated bi-center system, and multi-center redox-active organometallic compounds. Because of the presence of a metal-carbon bond on each metal component and strong electronic coupling between redox sites, these compounds display multiple reversible redox processes at low potentials and each redox state possesses significantly different physical and chemical properties. Using electrochemical potentials as input signals, these materials show reversible NIR absorption spectral changes, making them potentially useful in NIR electrochromism and information storage.

Synthesis and electrochemical and spectroscopic studies of a N,N,N＇,N＇- tetraphenylbenzidine-bridged bis(2,2＇-bipyridine) ligand and diruthenium complex

A N,N,N＇,N＇-tetraphenylbenzidine-bridged bis（2,2＇-bipyridine） ligand and corresponding diruthenium complexes were synthesized and characterized. They show rich multistep redox processes due to the stepwise oxidations of the amine units and ruthenium components. Their absorption and emission spectral changes in response to electrochemical stimulus were examined by spectroelectrochemical measurements. DFT and TDDFF calculations were performed to complement the experimental results.