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The energy loss (Eloss) caused by inefficient charge transfer and large energy level offset at the buried interface can easily restrict the performance of p-i-n perovskite solar cells (PVSCs). In this study, the utilization of poly-TPD and P3CT-N as a dual-hole transporting layer (HTLs) was implemented in a sequential manner. This approach aimed to improve the charge transfer efficiency of the HTL and mitigate charge recombination at the interface between the HTL and PVK. The results showed that this strategy also could achieve more suitable energy levels, improve the quality of the perovskite film layer, and ultimately enhance the device's stability. IPVSCs employing the dual-HTLs approach exhibited the highest power conversion efficiency of 19.85%, and the open-circuit voltage increased to 1.09 V from 1.00 V. This study offers a straightforward and efficient approach to boost the device performance by minimizing Eloss and reducing the buried interfacial defects. The findings underscore the potential of employing a dual-HTL strategy as a promising pathway for further advancements in PVSCs. [ABSTRACT FROM AUTHOR]

In this reported study, (Bi0.5Na0.5)0.93Ba0.07Ti1+xO3 (abbreviated as BNBT1+x) ceramics, containing Ti‐nonstoichiometry that ranged from a 2% deficiency to a 1% excess, were designed and systematically characterized. The results of the X‐ray diffraction Rietveld refinement and X‐ray photoelectron spectroscopy analysis of these materials revealed that the amount of Ti in the BNBT1+x ceramics significantly affected the degree of coexistent rhombohedral/tetragonal phases and also affected the content of singly/doubly charged oxygen‐vacancy (VO·/VO··) in the ceramics. After poling and 105 fatigue cycles, the variation in Raman resonance line‐width of the Ti–O bond in the BNBT1+x ceramics was found to be strongly dependent on the amount of Ti in the ceramic. The TiTi4+(3+)′-VO·→TiTi4+(3+)′-VO·· transformation and clustering of the TiTi4+(3+)′-VO·· defects under electrical loading were considered to be a critical factor in electric field‐induced structural transition and fatigue properties of the material. [ABSTRACT FROM AUTHOR]

With the increasing demand for compact storage systems for portable and wearable electronic devices, flexible supercapacitors with high volumetric performance have attracted considerable attention. Here, we report a simple method to fabricate a sandwich-like carbon nanotubes (CNTs)/NiCo2O4 hybrid paper electrode, consisting of a layer of conductive CNT buckypaper coated with honeycomb-like NiCo2O4 nanosheets at both sides. Owing to the high conductivity of the CNT skeleton and vertically aligned structure of NiCo2O4 nanosheets, the free-standing hybrid paper possesses an ultra-high specific capacitance of 1752.3 F g−1 and excellent cycling performance. A flexible all-solid-state symmetrical supercapacitor has been further assembled based on the hybrid paper. The device exhibits excellent volumetric energy and power densities (1.17 mW h cm−3 and 2430 mW cm−3) and deformability, even under bending at an angle of 180°. The hybrid paper can serve as a freestanding and flexible electrode for various energy devices. [ABSTRACT FROM AUTHOR]

Carbon films with the thicknesses varying from 10 to 600 nm in the architecture range of carbonaceous graphene to graphitic bonding were synthesized on Si wafer. The films were prepared by radio frequency plasma enhanced chemical vapor deposition under 300 °C without any catalyst and hydrogen-assistant ambient as well. The films found to be composed of microcrystalline graphene and graphite inclusions with a maximum graphene film size of 2 µm. Raman spectral characterization verified the bonding form of the graphene-graphitic films to be mostly sp. In this work, the complicated transfer printing process for carbon/silicon (C/Si) devices and the quality degradation of the hybrid films were avoided by the direct deposition of the carbonaceous films on Si substrate. The current-voltage feature of the devices manifested that the devices possess an excellent rectifying behavior in dark and the characteristic of photovoltaic in the illumination (known as solar cells). [ABSTRACT FROM AUTHOR]

Designing superb dielectric capacitors is valuable but challenging since achieving simultaneously large energy-storage (ES) density and high efficiency is difficult. Herein, the synergistic effect of grain refining, bandgap widening, and domain engineering is proposed to boost comprehensive ES properties by incorporating CaTiO 3 into 0.92NaNbO 3 -0.08BiNi 0.67 Ta 0.33 O 3 matrix (as abbreviated NN-BNT-xCT). Apart from grain refining and bandgap widening, multiple local distortions embedded in labyrinthine submicro-domains, as indicated by diffraction-freckle splitting and ½-type superlattices, produce slush-like polar clusters for the NN-BNT-0.2CT ceramic, which should be ascribed to the coexisting P4bm, P2 1 ma, and Pnma 2 phases. Consequently, a high recoverable ES density W rec of ≈ 7.1 J cm -3 and a high efficiency η of ≈ 90% at 646 kV cm -1 is achieved for the NN-BNT-0.2CT ceramic. Such hierarchically polar structure is favorable to superb comprehensive ES properties, which provide a strategy for developing high-performance dielectric capacitors., (© 2023 Wiley-VCH GmbH.)