Nanostructured ZnO electron transporting materials for hysteresis-free perovskite solar cell

An effective perovskite solar cell (PSC) usually reposes on perovskite absorber interfaced between an electron (ETL) and a hole transport layer (HTL), and outer electrodes. Planar zincite is viable for preparing PSCs with high power conversion efficiency (PCE) at low-temperatures due to appropriate electronic structure and physical properties. Recently, semiconductors with advanced geometries have attracted interest for ETLs. To rise up the specific surface area and thereof the charge transfer, zincite in nanorods configuration (ZNR) was tailored, but ZNR-PSCs show only limited increase of PCE due to considerable recombination in 1D ZNR. Methyl ammonium & formamidinium iodide (MAI, FAI) PSCs show highest PCE in ZNR-based devices, but still suffer from hysteresis and degradation. Finally, by eliminating the MAI from the composition, overall reach out to better fill factors and lower rate of hysteresis were achieved. Here we derived ZNR-(chemical-bath) PSCs without MAI (spin coated; assembled in protective atmosphere), to understand the preparing effects and influence on the overall PSC efficiency. Characterization using electric (J/V, EQE), structural (XRD) and morphologic (SEM) methods took place immediately upon PSC closure. Reliable interfacing of the layers can be confirmed, pointing out to importance of such configurations for the development of PSCs performance.