Strain Heterogeneity and Extended Defects in Halide Perovskite Devices.

Strain is an important property in halide perovskite semiconductors used for optoelectronic applications because of its ability to influence device efficiency and stability. However, descriptions of strain in these materials are generally limited to bulk averages of bare films, which miss important property-determining heterogeneities that occur on the nanoscale and at interfaces in multilayer device stacks. Here, we present three-dimensional nanoscale strain mapping using Bragg coherent diffraction imaging of individual grains in CsFAPb(IBr) and CsFASnI (FA = formamidinium) halide perovskite absorbers buried in full solar cell devices.

Novel 3D hierarchically structured cauliflower-shaped SnO nanospheres as effective photoelectrodes in hybrid photovoltaics.

Optical and electrical characteristics of wide bandgap metal oxides, namely the charge mobility, bandgap and energy level, directly define the performance and stability of photovoltaics. For the first time, novel three-dimensional (3D) hierarchically structured cauliflower-shaped SnO nanospheres with nanorods on their surface were obtained by a simple hydrothermal method without any additives at low temperature. The obtained hierarchically structured SnO nanospheres show large specific surface areas, proven to be efficient for sensitizer loading in both perovskite solar cells (PSCs) and dye-sensitized solar cells (DSSCs).

Co-axial electrospray: a versatile tool to fabricate hybrid electron transporting materials for high efficiency and stable perovskite photovoltaics.

We report a cost-effective and simple co-axial electrospray technique to fabricate a hybrid electron transporting material (ETM) consisting of a nanocomposite of hierarchically structured TiO nanobeads (NBs) blended with ZnO nanofibers (NFs), namely ZnO NFs + TiO NBs, for the first time ever. Owing to its large surface area, highly porous nature and fast electron transport, the hybrid ETM is further used in methylammonium lead iodide (CHNHPbI)-based perovskite solar cells (PSCs). The optimized cells utilizing the hybrid ETM exhibit a maximum power conversion efficiency (PCE) of 20.

Enhanced efficiency and stability of perovskite solar cells using polymer-coated bilayer zinc oxide nanocrystals as the multifunctional electron-transporting layer.

A novel polymer-coated ZnO based bilayer electron transporting material is investigated for highly efficiency perovskite solar cells. The bilayer ETM consisting of an upper-layer of ZnO nanosheets and a lower-layer of ZnO nanoparticles demonstrates the averaged power conversion efficiency of 13.11% and a maximum power conversion efficiency of 15.

Solution-processed barium hydroxide modified boron-doped ZnO bilayer electron transporting materials: Toward stable perovskite solar cells with high efficiency of over 20.5.

ZnO as an electron transporting material (ETM) in perovskite solar cells has many benefits, including low temperature processability and high mobility. We explore here for the first time, hysteresis-less mesostructured perovskite solar cells with an incredible steady-state efficiency of 20.62% particularly enhancement of the device stability.