Bridged Carbolong Modulating Interfacial Charge Transfer Enhancement for High-Performance Inverted Perovskite Solar Cells.

Efficient regulation of perovskite/C interface is crucial to improving the long-term stability of the inverted perovskite solar cells (PSCs). However, precise methods for controlling the perovskite/C interface have yet to be thoroughly explored. Herein, we develop a carbolong chemical manipulation strategy to improve the interface contact of perovskite/C due to versatile functional groups and excellent optoelectronic properties of carbolong metallaaromatics.

Triphenylamine-Functionalized Metal Nanoclusters for Efficient and Stable Perovskite Solar Cells.

Reported herein is a ligand engineering strategy to develop photoelectric active metal nanoclusters (NCs) with atomic precision. Triphenylamine (TPA), a typical organic molecule in the photoelectric field, is introduced for the first time to prepare atomically precise metal NCs that prove effective in the fabrication of perovskite solar cells (PSCs). The scalable synthetic prototype, unique electronic strucuture, and atomically precise structure of the cluster ([(AgCu)(PPh)(TPA-C≡C)]) are illustrated in this work.

Superoxide radical derived metal-free spiro-OMeTAD for highly stable perovskite solar cells.

Lithium salt-doped spiro-OMeTAD is widely used as a hole-transport layer (HTL) for high-efficiency n-i-p perovskite solar cells (PSCs), but unfortunately facing awkward instability for commercialization arising from the intrinsic Li migration and hygroscopicity. We herein demonstrate a superoxide radicals (•O) derived HTL of metal-free spiro-OMeTAD with remarkable capability of avoiding the conventional tedious oxidation treatment in air for highly stable PSCs. Present work explores the employing of variant-valence Eu(TFSI) salts that could generate •O for facile and adequate pre-oxidation of spiro-OMeTAD, resulting in the HTL with dramatically increased conductivity and work function.

Bilateral Chemical Linking at NiO Buried Interface Enables Efficient and Stable Inverted Perovskite Solar Cells and Modules.

Inverted NiO-based perovskite solar cells (PSCs) exhibit considerable potential because of their low-temperature processing and outstanding excellent stability, while is challenged by the carriers transfer at buried interface owing to the inherent low carrier mobility and abundant surface defects that directly deteriorates the overall device fill factor. Present work demonstrates a chemical linker with the capability of simultaneously grasping NiO and perovskite crystals by forming a Ni-S-Pb bridge at buried interface to significantly boost the carriers transfer, based on a rationally selected molecule of 1,3-dimethyl-benzoimidazol-2-thione (NCS). The constructed buried interface not only reduces the pinholes and needle-like residual PbI at the buried interface, but also deepens the work function and valence band maximum positions of NiO, resulting in a smaller VBM offset between NiO and perovskite film.

Conformal Imidazolium 1D Perovskite Capping Layer Stabilized 3D Perovskite Films for Efficient Solar Modules.

Although the perovskite solar cells have been developed rapidly, the industrialization of perovskite photovoltaics is still facing challenges, especially considering their stability issues. Here, the new type of benzimidazolium salt, N,N'-dialkylbenzimidazolium iodide, is proposed and functionalized to convert the three-dimensional (3D) FACs-perovskite films into one-dimensional (1D) capping layer topped 1D/3D structure either in individual device or module levels. This conformal interface modulation demonstrates that not only can effectively stabilize FACs-based perovskite films by inhibiting the lateral and vertical iodide diffusions in devices or modules, ensuring an excellent operation and environmental stability, but also provides an excellent charge transporting channel through the well-designed 1D crystal structure.

Sulfonate-Assisted Surface Iodide Management for High-Performance Perovskite Solar Cells and Modules.

Owing to the ionic nature of lead halide perovskites, their halide-terminated surface is unstable under light-, thermal-, moisture-, or electric-field-driven stresses, resulting in the formation of unfavorable surface defects. As a result, nonradiative recombination generally occurs on perovskite films and deteriorates the efficiency, stability, and hysteresis performances of perovskite solar cells (PSCs). Here, a surface iodide management strategy was developed through the use of cesium sulfonate to stabilize the perovskite surface.

Chemical Insights into Interfacial Effects in Inorganic Nanomaterials.

The interfaces between inorganic functional nanomaterials and their surface modifiers play important roles in determining their chemical and physical properties. In numerous situations, interfaces created by organic ligands or secondary inorganic components on inorganic nanomaterials induce significant effects to promote their performances. However, it still remains challenging to understand those interfacial effects at the molecular level.

Methylamine-Dimer-Induced Phase Transition toward MAPbI Films and High-Efficiency Perovskite Solar Modules.

Perovskite films prepared with CHNH molecules under ambient conditions have led to rapid fabrication of perovskite solar cells (PSCs), but there remains a lack of mechanistic studies and inconsistencies with operability in their production. Here the crystal structure of CHNH-CHNHPbI was analyzed to involve hydrogen bonds (CHNH···CHNH) and has guided the facile, reproducible preparation of high-quality perovskite films under ambient conditions. Hydrogen bonds within CHNH···CHNH dimers were found in the CHNH-CHNHPbI intermediates, accompanied by 1D-PbI chains (δ-phase).

Light-Trapping Engineering for the Enhancements of Broadband and Spectra-Selective Photodetection by Self-Assembled Dielectric Microcavity Arrays.

Light manipulation has drawn great attention in photodetectors towards the specific applications with broadband or spectra-selective enhancement in photo-responsivity or conversion efficiency. In this work, a broadband light regulation was realized in photodetectors with the improved spectra-selective photo-responsivity by the optimally fabricated dielectric microcavity arrays (MCAs) on the top of devices. Both experimental and theoretical results reveal that the light absorption enhancement in the cavities is responsible for the improved sensitivity in the detectors, which originated from the light confinement of the whispering-gallery-mode (WGM) resonances and the subsequent photon coupling into active layer through the leaky modes of resonances.

Perfection of Perovskite Grain Boundary Passivation by Eu-Porphyrin Complex for Overall-Stable Perovskite Solar Cells.

The formation of defects at surfaces and grain boundaries (GBs) during the fabrication of solution-processed perovskite film are thought to be responsible for its instability. Herein, Eu-porphyrin complex (Eu-pyP) is directly doped into methylammonium lead triiodide (MAPbI) precursor, perfectly fabricating 2D (Eu-pyP)MA Pb I platelets inlaying the GBs of 3D polycrystalline interstices in this protocol. The device based on Eu-pyP doped perovskite film possesses a champion efficiency of 18.

Monoammonium Porphyrin for Blade-Coating Stable Large-Area Perovskite Solar Cells with >18% Efficiency.

Efficient control of crystallization and defects of perovskite films are the key factors toward the performance and stability of perovskite solar cells (PSCs), especially for the preparation of large-area PSCs devices. Herein, we directly embedded surfactant-like monoammonium zinc porphyrin (ZnP) compound into the methylammonium (MA) lead iodide perovskite film to blade-coat large-area uniform perovskite films as large as 16 cm. Efficiency as high as 18.

High-Efficiency, Hysteresis-Less, UV-Stable Perovskite Solar Cells with Cascade ZnO-ZnS Electron Transport Layer.

Perovskite solar cells (PSCs) have reached certified efficiencies of up to 23.7% but suffered from frailness and instability when exposed to ambient atmosphere. Zinc oxide (ZnO), when used as electron transport layer (ETL) on PSCs, gives rise to excellent electronic, optic, and photonic properties, yet the Lewis basic nature of ZnO surface leads to deprotonation of the perovskite layer, resulting in serious degradation of PSCs using ZnO as ETL.

Ether-Soluble Cu Nanoclusters as an Effective Precursor of High-Quality CuI Films for Optoelectronic Applications.

An effective strategy is developed to synthesize high-nuclearity Cu clusters, [Cu (RCOO) (C≡CtBu) Cl H ] (Cu ), which is the largest Cu /Cu cluster reported to date. Cu powder and Ph SiH are employed as the reducing agents in the synthesis. As revealed by single-crystal diffraction, Cu is arranged as a four-concentric-shell Cu @Cu Cl @Cu @Cu structure, possessing an atomic arrangement of concentric M icosahedral and M dodecahedral shells which popularly occurs in Au/Ag nanoclusters.

Efficient, Hysteresis-Free, and Stable Perovskite Solar Cells with ZnO as Electron-Transport Layer: Effect of Surface Passivation.

The power conversion efficiency of perovskite solar cells (PSCs) has ascended from 3.8% to 22.1% in recent years.

Identifying the Molecular Structures of Intermediates for Optimizing the Fabrication of High-Quality Perovskite Films.

During the past two years, the introduction of DMSO has revolutionized the fabrication of high-quality pervoskite MAPbI3 (MA = CH3NH3) films for solar cell applications. In the developed DMSO process, the formation of (MA)2Pb3I8·2DMSO (shorted as Pb3I8) has well recognized as a critical factor to prepare high-quality pervoskite films and thus accomplish excellent performances in perovskite solar cells. However, Pb3I8 is an I-deficient intermediate and must further react with methylammonium iodide (MAI) to be fully converted into MAPbI3.

Linear and stable photonic radio frequency phase shifter based on a dual-parallel Mach-Zehnder modulator using a two-drive scheme.

We theoretically and experimentally demonstrate a linear and stable photonic RF phase shifter based on a dual-parallel Mach-Zehnder modulator (DPMZM) using a two-drive scheme. To avoid the effect of the residual optical carrier and overcome the lowest frequency limit from the optical filter, a local microwave signal and a signal up-converted from the under-phase-shifted RF signal are applied to the two RF inputs of the DPMZM, respectively. A phase-shifted RF signal is generated by beating the two first-order upper sidebands located in the passband of the optical filter.

Promoting effect of layered titanium phosphate on the electrochemical and photovoltaic performance of dye-sensitized solar cells.

We reported a composite electrolyte prepared by incorporating layered α-titanium phosphate (α-TiP) into an iodide-based electrolyte using 1-ethyl-3-methylimidazolium tetrafluoroborate(EmimBF4) ionic liquid as solvent. The obtained composite electrolyte exhibited excellent electrochemical and photovoltaic properties compared to pure ionic liquid electrolyte. Both the diffusion coefficient of triiodide (I3-) in the electrolyte and the charge-transfer reaction at the electrode/electrolyte interface were improved markedly.