Single-Layered MXene Nanosheets Doping TiO for Efficient and Stable Double Perovskite Solar Cells.

The inorganic lead-free CsAgBiBr double perovskite structure is the promising development direction in perovskite solar cells (PSCs) to solve the problem of the instability of the APbX structure and lead toxicity. However, the low short-circuit current and power conversion efficiency (PCE) caused by the low crystallization of CsAgBiBr greatly limit the optoelectronic application. Herein, we adopt a simple strategy to dope single-layered MXene nanosheets into titania (TiCT@TiO) as a multifunctional electron transport layer for stable and efficient CsAgBiBr double PSCs.

UV-Stable and Highly Efficient Perovskite Solar Cells by Employing Wide Band gap NaTaO as an Electron-Transporting Layer.

Organic-inorganic halide perovskite solar cells (PSCs) still suffer from stability issues which are caused by possible erosions from moisture, ultraviolet (UV) light, heat, and so forth. An electron-transporting layer (ETL), that is, TiO, is a key component for state-of-the-art PSCs. However, UV-caused desorption of O in TiO would accelerate the degradation of PSCs.

Lead Oxalate-Induced Nucleation Retardation for High-Performance Indoor and Outdoor Perovskite Photovoltaics.

Perovskite solar cells have attracted worldwide attention as one of the key research areas in the field of thin-film photovoltaics. Although they exhibit easy solution processability, it is important to effectively control the crystallization of the light-absorbing layer, which affects the performance and stability of devices. Here, we present lead oxalate (PbCO) as a nonhalide lead constituent of the perovskite precursor solution, which contributes to anion replacement during thin film annealing.

Composition Stoichiometry of CsAgBiBr Films for Highly Efficient Lead-Free Perovskite Solar Cells.

Addressing the toxicity issue in lead-based perovskite compounds by seeking other nontoxic candidate elements represents a promising direction to fabricate lead-free perovskite solar cells. Recently, CsAgBiBr double perovskite achieved by replacing two Pb with Ag and Bi in the crystal lattice has drawn much attention owing to the convenient substitution of its chemical compositions. Herein, the dependence of the optoelectronic properties and corresponding photovoltaic performance of CsAgBiBr thin films on the deposition methods of vacuum sublimation and solution processing is investigated.

Efficiency Enhancement of Perovskite Solar Cells by Pumping Away the Solvent of Precursor Film Before Annealing.

A new approach to improve the quality of MAPbI3 - x Cl x perovskite film was demonstrated. It involves annealing the precursor film after pumping away the solvent, which can decrease the influence of solvent evaporation rate for the growth of the MAPbI3 - x Cl x perovskite film. The resulting film showed improved morphology, stronger absorption, fewer crystal defects, and smaller charge transfer resistance.

Origin of Enhanced Hole Injection in Organic Light-Emitting Diodes with an Electron-Acceptor Doping Layer: p-Type Doping or Interfacial Diffusion?

The electrical doping nature of a strong electron acceptor, 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (HATCN), is investigated by doping it in a typical hole-transport material, N,N'-bis(naphthalen-1-yl)-N,N'-diphenylbenzidine (NPB). A better device performance of organic light-emitting diodes (OLEDs) was achieved by doping NPB with HATCN. The improved performance could, in principle, arise from a p-type doping effect in the codeposited thin films.