Heteropolymer improves p-i junction in perovskite solar cells.

The p-i heterojunction imbedded underneath the perovskite layer plays a vital role in determining the efficiency and stability of inverted perovskite solar cells (PSCs). We found that poly[bis(4-phenyl) (2,4,6-trimethylphenyl) amine] (PTAA) suffers from the severely chain entanglement resulting in poor contact with perovskite. In this work, PTAA layer was treated by poly[(2,6-(4,8-bis(5-(2-ethylhexylthio)-4-fluorothiophen-2-yl)-benzo[1,2-b:4,5-b'] dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl) benzo[1',2'-c:4',5'-c'] dithiophene-4,8-dione)] (PBDB-T-SF) diluted solution in chlorobenzene.

Quenching Detrimental Reactions and Boosting Hole Extraction via Multifunctional NiO /Perovskite Interface Passivation for Efficient and Stable Inverted Solar Cells.

Nickel oxide (NiO ) is one of the most promising hole transport materials for inverted perovskite solar cells (PSCs). However, its application is severely restrained due to unfavorable interfacial reactions and insufficient charge carrier extraction. Herein, a multifunctional modification at the NiO /perovskite interface is developed via introducing fluorinated ammonium salt ligand to synthetically solve the obstacles.

Dual Optimization of Bulk and Interface via the Synergistic Effect of Ligand Anchoring and Hole Transport Dopant Enables 23.28% Efficiency Inverted Perovskite Solar Cells.

The crystalline morphology of perovskite film plays a key role in determining the stability and performance of perovskite solar cells (PSCs). In addition, the work function and conductivity of hole transport layer (HTL) have a great influence on the effciency of PSCs. Here, we develop a synergistic doping strategy to fabricate high-performance inverted PSCs, doping a functional nanographene (C-AHM) into the poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine (PTAA) HTL, thus forming an HTL with higher conductivity, lower roughness, and frontier energy levels matching the perovskite absorber work function.

Integrated Ideal-Bandgap Perovskite/Bulk-Heterojunction Solar Cells with Efficiencies > 24.

Here, the authors report a highly efficient integrated ideal-bandgap perovskite/bulk-heterojunction solar cell (IPBSC) with an inverted architecture, featuring a near infrared (NIR) polymer DTBTI-based bulk-heterojunction (BHJ) layer atop guanidinium bromide (GABr)-modified FA MA Pb Sn I perovskite film as the photoactive layer. The IPBSC shows cascade-like energy level alignment between the charge-extractionlayer/perovskite/BHJ and efficient passivation effect of BHJ on perovskite. Thanks to the well-matched energy level alignment and high-quality ideal bandgap-based perovskite film, an efficient charge transfer occurs between the charge-extraction-layer/perovskite/BHJ.

Highly Orientational Order Perovskite Induced by In situ-generated 1D Perovskitoid for Efficient and Stable Printable Photovoltaics.

Employing low-dimensional perovskite has been proven to be a promising approach to enhance the efficiency and stability of perovskite solar cells. Here, thiopheniformamidine hydrochloride is introduced into CH NH PbI -based printable mesoscopic perovskite solar cells, to form 1D iodide lead thiophenamidine (TFPbI ) in situ. This judiciously designed low-dimensional perovskite can effectively passivate the defect of perovskite and induce the perovskite crystals to grow in a direction perpendicular to the substrate.

Water-Soluble Conjugated Polyelectrolyte Hole Transporting Layer for Efficient Sky-Blue Perovskite Light-Emitting Diodes.

An optimized charge transporting layer (CTL) under perovskite film is crucial for efficient photoelectric devices. Here, a new water-soluble conjugated polyeletrolyte (CPE) with CH NH (MA ) counterion termed as TB(MA) is used as the hole transporting layer (HTL) instead of the acidic poly(3,4-ethylenedioxythiophene):poly-styrene sulfonate (PEDOT:PSS) in sky-blue perovskite light-emitting diodes (PeLEDs). The inherent hydrophilicity of CPE enables a well-growth of quasi-2D perovskite layer with uniform and compact morphology, enhanced crystallinity with rare defect density and excellent energy transfer, resulting in a high photoluminescence quantum yield (PLQY) up to 62.

A dual function-enabled novel zwitterion to stabilize a Pb-I framework and passivate defects for highly efficient inverted planar perovskite solar cells.

A novel zwitterion named bethanechol chloride (BTCC) was introduced to simultaneously stabilize a Pb-I framework and passivate defects for efficient inverted perovskite solar cells. The BTCC-assisted device yielded an elevated power conversion efficiency of 20.45% with an open-circuit voltage of 1.

Highly Efficient and Stable GABr-Modified Ideal-Bandgap (1.35 eV) Sn/Pb Perovskite Solar Cells Achieve 20.63% Efficiency with a Record Small V Deficit of 0.33 V.

1.5-1.6 eV bandgap Pb-based perovskite solar cells (PSCs) with 30-31% theoretical efficiency limit by the Shockley-Queisser model achieve 21-24% power conversion efficiencies (PCEs).

Side-Chain Polymers as Dopant-Free Hole-Transporting Materials for Perovskite Solar Cells-The Impact of Substituents' Positions in Carbazole on Device Performance.

Side-chain polymers have the potential to be excellent dopant-free hole-transporting materials (HTMs) for perovskite solar cells (PSCs) because of their unique characteristics, such as tunable energy levels, high charge mobility, good solubility, and excellent film-forming ability. However, there has been less research focusing on side-chain polymers for PSCs. Here, two side-chain polystyrenes with triphenylamine substituents on carbazole moieties were designed and characterized.

High-Performance Sodium-Ion Batteries Based on Nitrogen-Doped Mesoporous Carbon Spheres with Ultrathin Nanosheets.

Hard carbon exhibits high theoretical capacity for sodium-ion batteries. However, its practical application suffers from low electric conductivity, poor electrochemical stability, and sluggish kinetics. To tackle these challenges, novel nitrogen-doped carbon spheres with mesopores, ultrathin nanostructure, and optimal graphitization are prepared by a three-step procedure.

Evaluation of A-Site Ba-Deficient Ba CoFeZrYO Oxides as Electrocatalysts for Efficient Hydrogen Evolution Reaction.

Exploring earth-abundant and cost-effective catalysts with high activity and stability for a hydrogen evolution reaction (HER) is of great importance to practical applications of alkaline water electrolysis. Here, we report on A-site Ba-deficiency doping as an effective strategy to enhance the electrochemical activity of BaCoFeZrYO for HER, which is related to the formation of oxygen vacancies around active Co/Fe ions. By comparison with the benchmarking BaSrCoFeO , one of the most spotlighted perovskite oxides, the BaCoFeZrYO oxide has lower overpotential and smaller Tafel slope.

Intensive Exposure of Functional Rings of a Polymeric Hole-Transporting Material Enables Efficient Perovskite Solar Cells.

A variety of dopant-free hole-transporting materials (HTMs) is effectively applied in perovskite solar cells (PSCs); however, HTMs with the additional function of HTM/perovskite interfacial optimization that is crucial to their photovoltaic performance are really limited. In this work, the design of an HTM bearing an intensive exposure of its functional aromatic rings to perovskite layer via side-chain engineering is attempted. With an edge-on orientation and a short distance to perovskite, this HTM was expected to display an excellent ability to extract holes from and passivate defects in the perovskite layer.

Toward Highly Sensitive Polymer Photodetectors by Molecular Engineering.

Modified 3,4-ethylenedioxythiophene is employed as the conjugated side chain in conjugated polymers, which can significantly depress the dark current of the polymer photodetectors with little associated decrease in photovoltaic properties, thus enhanceing the detectivities. This approach can be applied to a variety of conjugated polymers covering a photoresponse range from UV to NIR.

Synthesis and application of poly(fluorene-alt-naphthalene diimide) as an n-type polymer for all-polymer solar cells.

A new alternating copolymer of fluorene and naphthalene diimide, PF-NDI, was synthesized and characterized. The highest power conversion efficiency of all-polymer solar cells based on P3HT:PF-NDI reached 1.63% with a relatively high fill factor of 0.

Effects of block length in copolymers based on regioregular oligothiophenes linked with electron-accepting units.

Copolymers with an alternating structure of regioregular oligo(3-hexylthiophene) (O3HT) with different lengths and 2,5-dibutyl-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (DPP) were synthesized through Stille coupling reaction. The light absorption of the copolymers can be rationally tuned to have a broad spectrum across the visible region by adjusting the length of O3HT. Organic solar cells fabricated with the copolymers and PCBM showed a broad photoresponse and a comparable efficiency to that of poly(3-hexylthiophene) (P3HT):PCBM cells.