In-Situ Cyclized Polyacrylonitrile as an Electron Selective Layer for n-i-p Perovskite Solar Cell with Enhanced Efficiency and Stability.

In situ cyclized polyacrylonitrile (CPAN) is developed to replace n-type metal oxide semiconductors (TiO or SnO) as an electron selective layer (ESL) for highly efficient and stable n-i-p perovskite solar cells (PSCs). The CPAN layer is fabricated via facile in situ cyclization reaction of polyacrylonitrile (PAN) coated on a conducting glass substrate. The CPAN layer is robust and insoluble in common solvents, and possesses n-type semiconductor properties with a high electron mobility of 4.

Organic-inorganic hybrid perovskite for low-cost and high-performance xerographic photoreceptors.

Solution-processable organic-inorganic hybrid perovskites are being widely investigated for many applications, including solar cells, light-emitting diodes, photodetectors, and lasers. Herein, we report, for the first time, successful fabrication of xerographic photoreceptors using methylammonium lead iodide (CHNHPbI) perovskite as a light-absorbing material. With the incorporation of polyethylene glycol (PEG) into the perovskite film, the ion migration inherent to the perovskite material can be effectively suppressed, and the resulting photoreceptor exhibits a high and panchromatic photosensitivity, large surface potential, low dark decay, and high environmental resistance and electrical cycling stability.

Full-Electrochemical Construction of High-Performance Polypyrrole/Tellurium Thermoelectrical Nanocomposites.

As one of the most attractive inorganics to improve the thermoelectric (TE) performance of the conducting polymers, tellurium (Te) has received intense concern due to its superior Seebeck coefficient (). However, far less attention has been paid to polypyrrole (PPy)/Te TE composites to date. In this work, we present an innovative full-electrochemical method to architect PPy/Te TE composite films by sequentially depositing Te with large and PPy with high electrical conductivity (σ).

Facile Modification of a Noncovalently Fused-Ring Electron Acceptor Enables Efficient Organic Solar Cells.

Electron acceptors with nonfused aromatic cores (NCAs) have aroused increasing interest in organic solar cells due to the low synthetic complexity and flexible chemical modification, but the corresponding device performance still lags behind. Herein, we designed and synthesized two new quinoxaline-based NCAs, namely, QOC6-4H and QOC6-4Cl. Although both NCAs show good backbone coplanarity, QOC6-4Cl with chlorinated end groups exhibits higher extinction coefficient, enhanced crystallinity, and more compact π-π stacking, which is correlated with the stronger intermolecular interactions induced by chlorine atoms.

Pseudo construction of high-performance thermoelectric composites with a dioxothiopyrone-based D-A polymer coating on SWCNTs.

Organic polymer/inorganic particle composites with thermoelectric (TE) properties have witnessed rapid progress in recent years. Nevertheless, both development of novel polymers and optimization of compositing methods remain highly desirable. In this study, we first demonstrated a simulated coagulation strategy for construction of high-performance thermoelectric materials by utilizing single-walled carbon nanotubes (SWCNTs) and a new D-A polymer TPO-TTP12 that was synthesized incorporating dioxothiopyrone subunit into a polymeric chain.

Methylamine-assisted growth of uniaxial-oriented perovskite thin films with millimeter-sized grains.

Defects from grain interiors and boundaries of perovskite films cause significant nonradiative recombination energy loss, and thus perovskite films with controlled crystallinity and large grains is critical for improvement of both photovoltaic performance and stability for perovskite-based solar cells. Here, a methylamine (MA) gas-assisted crystallization method is developed for fabrication of methylammonium lead iodide (MAPbI) perovskite films. In the process, the perovskite film is formed via controlled release of MA0 gas molecules from a liquid intermediate phase MAPbI·xMA.

Ion Exchange/Insertion Reactions for Fabrication of Efficient Methylammonium Tin Iodide Perovskite Solar Cells.

The low toxicity, narrow bandgaps, and high charge-carrier mobilities make tin perovskites the most promising light absorbers for low-cost perovskite solar cells (PSCs). However, the development of the Sn-based PSCs is seriously hampered by the critical issues of poor stability and low power conversion efficiency (PCE) due to the facile oxidation of Sn to Sn and poor film formability of the perovskite films. Herein, a synthetic strategy is developed for the fabrication of methylammonium tin iodide (MASnI) film via ion exchange/insertion reactions between solid-state SnF and gaseous methylammonium iodide.

-BuOK-catalysed alkylation of fluorene with alcohols: a highly green route to 9-monoalkylfluorene derivatives.

A simple, mild and efficient protocol was developed for the alkylation of fluorene with alcohols in the presence of -BuOK as catalyst, affording the desired 9-monoalkylfluorenes with near quantitative yields in most cases.

A Novel Strategy for Scalable High-Efficiency Planar Perovskite Solar Cells with New Precursors and Cation Displacement Approach.

Methylammonium iodide (MAI) and lead iodide (PbI ) have been extensively employed as precursors for solution-processed MAPbI perovskite solar cells (PSCs). However, the MAPbI perovskite films directly deposited from the precursor solutions, usually suffer from poor surface coverage due to uncontrolled nucleation and crystal growth of the perovskite during the film formation, resulting in low photovoltaic conversion efficiency and poor reproducibility. Herein, propylammonium iodide and PbI are employed as precursors for solution deposition of propylammonium lead iodide (PAPbI ) perovskite film.

Direct Conversion of CH3NH3PbI3 from Electrodeposited PbO for Highly Efficient Planar Perovskite Solar Cells.

Organic-inorganic hybrid perovskite materials have recently been identified as a promising light absorber for solar cells. In the efficient solar cells, the perovskite active layer has generally been fabricated by either vapor deposition or two-step sequential deposition process. Herein, electrochemically deposited PbO film is in situ converted into CH3NH3PbI3 through solid-state reaction with adjacent CH3NH3I layer, exhibiting a large-scale flat and uniform thin film with fully substrate coverage.

Nickel-catalyzed triarylamine synthesis: synthetic and mechanistic aspects.

An improved protocol was described for the amination of chloroarenes with diarylamines under NiCl2(PCy3)2 catalysis in the presence of a Grignard reagent as base. This method fully suits bromo-/iodoarene substrates as well, and even is expanded to certain aryl tosylates. A preliminary investigation into the mechanism suggests that this amination reaction might proceed through Ni(I) and Ni(III) intermediates rather than via the usually expected Ni(0)-Ni(II) cycle.

Iron(III)-promoted oxidative coupling of naphthylamines: synthetic and mechanistic investigations.

A facile route to the synthesis of 1,1'-binaphthyl-4,4'-diamines (naphthidines) and 1,1'-binaphthyl-2,2'-diamines (BINAMs) was developed by the oxidative homocoupling of 1- and 2-naphthylamines, respectively, using FeCl(3) as oxidant and K(2)CO(3) as base in 1,2-dichloroethane under ambient conditions. A preliminary mechanistic investigation was performed by the ESR spectroscopy and intermediate-trapping technique.

Nickel-catalyzed amination of aryl phosphates through cleaving aryl C-O bonds.

The amination of triaryl phosphates was achieved using a Ni(II)-(σ-Aryl) complex/NHC catalyst system in dioxane at 110 °C in the presence of NaH as base. Electron-neutral, -rich, and -deficient triaryl phosphates were coupled with a wider range of amine partners including cyclic and acyclic secondary amines, aliphatic primary amines, and anilines in good to excellent yields.

P3HT as hole transport material and assistant light absorber in CdS quantum dots-sensitized solid-state solar cells.

Regioregular poly(3-hexylthiophene) (P3HT) was employed as a hole transport material and assistant light absorber for the fabrication of a CdS quantum dot-sensitized solid-state solar cell, by which a power-conversion efficiency of 1.42% was achieved under an AM1.5 G (100 mW cm(-2)) condition.

Nickel-catalyzed cross-coupling of diarylamines with haloarenes.

The cross-coupling reaction of diarylamines with aryl bromides/iodides can be effected by the Ni(ii)-(sigma-aryl) complex/PPh(3)/NaH system, and a preliminary investigation was conducted into the mechanism of this reaction.

Novel TPD-based organic D-pi-A dyes for dye-sensitized solar cells.

A novel class of organic D-pi-A dyes employing a N,N,N',N'-tetraphenylbenzidine (TPD) unit as donor was designed and synthesized for dye-sensitized solar cells, which achieved a solar-to-electricity conversion efficiency (eta) of 5.63% in preliminary tests as compared to 6.42% for N3 dye under the same experimental conditions.

Nickel-catalyzed amination of aryl tosylates.

The cross-coupling of aryl tosylates with amines and anilines was accomplished by using a Ni-based catalyst system from the combination of Ni(II)-(sigma-aryl) complexes/N-heterocyclic carbenes (NHCs). The feature, scope, and limitation of this reaction are disclosed.

trans-(4-Acetyl-naphth-yl)chlorido-bis(triphenyl-phosphine-κP)nickel(II) dichloro-methane solvate.

The title compound, [Ni(C(12)H(9)O)Cl(C(18)H(15)P)(2)]·CH(2)Cl(2), was synthesized from the reaction between 1-acetyl-4-chloro-naphthalene, NiCl(2)·6H(2)O and triphenyl-phosphine (PPh(3)) in ethanol. The compound contains one crystallographically unique nickel ion in a pseudo-square-planar geometry.

Ni(II)-(sigma-aryl) complex: a facile, efficient catalyst for nickel-catalyzed carbon-nitrogen coupling reactions.

trans-Haloarylbis(triphenylphosphine)nickel(II), a type of air- and moisture-stable Ni(II)-(sigma-aryl) complex, was examined as catalyst precursor in the C-N coupling reaction. This type of Ni(II) pre-catalyst, associated with N-heterocyclic carbene ligands, is found to easily produce the catalytically active Ni(0) species in situ without the aid of external reductants and allows for the efficient amination of aryl chlorides with secondary cyclic amines and anilines under mild conditions.

Novel organic dyes for efficient dye-sensitized solar cells.

Two novel metal-free organic dyes containing thienothiophene and thiophene segments have been synthesized. Nano-crystalline TiO2 dye-sensitized solar cells were fabricated using these dyes as light-harvesting sensitizers, and a high solar energy-to-electricity conversion efficiency of 6.23% was achieved.

Arylation of diarylamines catalyzed by Ni(II)-PPh3 system.

[reaction: see text]. The cross-coupling of bromomagnesium diarylamides, generated in situ from diarylamines, with aryl bromides or iodides can be effected with a simple NiCl2(PPh3)2-PPh3 catalyst system under relatively mild conditions. This coupling reaction is an inexpensive, convenient, and practical method, functioning as an alternative to the corresponding Pd-catalyzed or Cu-mediated process for the synthesis of triarylamines.