Interstitial iodides are the most critical type of defects in perovskite solar cells that limits efficiency and stability. They can be generated during solution, film, and device processing, further accelerating degradation. Herein, we find that introducing a small amount of a zinc salt- zinc trifluoromethane sulfonate (Zn(OOSCF)) in the perovskite solution can control the iodide defects in resultant perovskites ink and films.
View Article and Find Full Text PDFMetal-halide perovskites (MHPs) have been successfully exploited for converting photons to charges or vice versa in applications of solar cells, light-emitting diodes and solar fuels, for which all these applications involve strong light. Here we show that self-powered polycrystalline perovskite photodetectors can rival the commercial silicon photomultipliers (SiPMs) for photon counting. The photon-counting capability of perovskite photon-counting detectors (PCDs) is mainly determined by shallow traps, despite that deep traps also limit charge-collection efficiency.
View Article and Find Full Text PDFTin-lead (Sn-Pb) narrow-bandgap (NBG) perovskites show great potential in both single-junction and all-perovskite tandem solar cells. Sn-Pb perovskite solar cells (PSCs) are still limited by low charge collection efficiency and poor stability. Here, a ternary Sn (II) alloy of SnOCl is reported as the hole-transport material (HTM) with a work function of 4.
View Article and Find Full Text PDFThe formation of voids in perovskite films close to the buried interface has been reported during film deposition. These voids are thought to limits the efficiency and stability of perovskite solar cells (PSCs). Here, we studied the voids formed during operation in perovskite films that were optimized during the solution deposition process to avoid voids.
View Article and Find Full Text PDFPerovskite solar cells (PSCs) are promising to reduce the cost of photovoltaic system due to their low-cost raw materials and high-throughput solution process; however, fabrication of all the active layers in perovskite modules using a scalable solution process has not yet been demonstrated. Herein, the fabrication of highly efficient PSCs and modules in ambient conditions is reported, with all layers bladed except the metal electrode, by blading a 36 ± 9 nm-thick electron-transport layer (ETL) on perovskite films with a roughness of ≈80 nm. A combination of additives in phenyl-C -butyric acid methyl ester (PCBM) allows the PCBM to conformally cover the perovskites and still have a good electrical conductivity.
View Article and Find Full Text PDFMetal halide perovskite nanocrystals have recently emerged as promising materials for light emitting displays and lasing applications due to their narrow emission wavelengths, high photoluminescence quantum yields, and readily adjustable emission wavelengths. For these metal halide perovskite nanocrystals to be useful in commercial applications, their stability must be increased and the photoluminescence quantum yields of the iodide (red emitting) and chloride (blue emitting) containing derivatives must also be increased. The photoluminescence quantum yields of blue emitting CsPbCl3 nanoparticles lag behind those of green emitting CsPbBr3 nanoparticles, with maximum photoluminescence quantum yields of 1-10% previously reported for CsPbCl3 as compared to 80-100% for CsPbBr3.
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