The evolution of defects during perovskite film fabrication deteriorates the overall film quality and adversely affects the device efficiency of perovskite solar cells (PSCs). We endeavored to control the formation of defects by applying an additive engineering strategy using FABr, which retards the crystal growth formation of CsPbIBr perovskite by developing an intermediate phase at the initial stage. Improved crystalline and pinhole-free perovskite film with an optimal concentration of FABr-0.
View Article and Find Full Text PDFAll-inorganic CsPbIBr (CPIB) perovskite has gained strong attention due to their favorable optoelectronic properties for photovoltaics. However, solution-processed CPIB films suffer from poor morphology due to the rapid crystallization process, which must be resolved for desirable photovoltaic performance. We introduced phenethylammonium iodide (PEAI) as an additive into a perovskite precursor that effectively controls the crystallization kinetics to construct the preferred quality α-CPIB film under ambient conditions.
View Article and Find Full Text PDFWe demonstrate synthesis of a new low-D hybrid perovskitoid (a perovskite-like hybrid halide structure, yellow crystals, P21/n space group) using zwitterion cysteamine (2-aminoethanethiol) linker, and its remarkable molecular diffusion-controlled crystal-to-crystal transformation to Ruddlesden-Popper phase (Red crystals, Pnma space group). Our stable intermediate perovskitoid distinctly differs from all previous reports by way of a unique staggered arrangement of holes in the puckered 2D configuration with a face-sharing connection between the corrugated-1D double chains. The PL intensity for the yellow phase is 5 orders higher as compared to the red phase and the corresponding average lifetime is also fairly long (143 ns).
View Article and Find Full Text PDFThe dynamics and control of charge transfer between optoelectronically interesting and size-tunable halide perovskite quantum dots and other juxtaposed functional electronic materials are important issues for the emergent device interest involving such a family of materials in heterostructure configurations. Herein, we have grown bimetallic Au-Ag thin films on glass by pulsed laser deposition at room temperature, which bear nanoparticulate character, and the corresponding optical absorption spectra reveal the expected surface plasmon resonance signature(s). Subsequently, spin-coated CsPbBr nanoparticle films onto the bimetallic Au-Ag films exhibit surface-enhanced Raman scattering as well as strong photoluminescence quenching, the latter reflecting highly efficient transfer of photo-generated carriers across the CsPbBr/Au-Ag interface.
View Article and Find Full Text PDFLead-free hybrid and inorganic perovskites (A CuBr ; A=CH NH or Cs, 2 D or3 D) are synthesized by a room-temperature solid-state reaction route and examined as anode materials in Li-ion batteries. A remarkably high reversible capacity of 630 mAh g is realized in the 2 D hybrid perovskite at 100 mA g at the end of 140 cycles. A full cell with this anode is also tested and shows impressive cycling stability.
View Article and Find Full Text PDFAn ordered self-assembly of CsPbBr quantum dots (QDs) was generated on the surface of few-layer black phosphorus (FLBP). Strong quenching of the QD fluorescence was observed, and analyzed by time-resolved photoluminescence (TR-PL) studies, DFT calculations, and photoconductivity measurements. Charge transfer by type I band alignment is suggested to be the cause of the observed effects.
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