Caixing Wang

CsPb0.9Sn0.1IBr2 Based All-Inorganic Perovskite Solar Cells with Exceptional Efficiency and Stability

The emergence of perovskite solar cells (PSCs) has generated enormous interest in the photovoltaic research community. Recently, cesium metal halides (CsMX3, M = Pb or Sn; X = I, Br, Cl or mixed halides) as a class of inorganic perovskites showed great promise for PSCs and other optoelectronic devices. However, CsMX3-based PSCs usually exhibit lower power conversion efficiencies (PCEs) than organic-inorganic hybrid PSCs, due to the unfavorable band gaps. Herein, a novel mixed-Pb/Sn mixed-halide inorganic perovskite, CsPb0.9Sn0.1IBr2, with a suitable band gap of 1.79 eV and an appropriate level of valence band maximum, was prepared in ambient atmosphere without a glovebox. After thoroughly eliminating labile organic components and noble metals, the all-inorganic PSCs based on CsPb0.9Sn0.1IBr2 and carbon counter electrodes exhibit a high open-circuit voltage of 1.26 V and a remarkable PCE up to 11.33%, which is record-breaking among the existing CsMX3-based PSCs. Moreover, the all-inorganic PSCs show good long-term stability and improved endurance against heat and moisture. This study indicates a feasible way to design inorganic halide perovskites through energy-band engineering for the construction of high-performance all-inorganic PSCs.

Correction to “All-Inorganic Perovskite Solar Cells”

Figure 3. (a) J−V plot of CsPbBr3/carbon-based all-inorganic PSCs. The inset shows the corresponding photovoltaic parameters. (b) Statistical histogram of the PCEs of 40 individual CsPbBr3/ carbon-based all-inorganic PSCs. (c) Normalized PCEs of CsPbBr3/ carbon-based all-inorganic PSCs and MAPbI3/carbon-based and MAPbI3/spiro-MeOTAD-based hybrid PSCs as a function of storage time in humid air (90−95% RH, 25 °C) without encapsulation. (d) Normalized PCEs of CsPbBr3/carbon-based all-inorganic PSCs and MAPbI3/carbon-based hybrid PSCs as a function of time heated at high temperature (100 °C) in a high-humidity ambient environment (90−95% RH, 25 °C) without encapsulation. (e) Normalized PCEs of CsPbBr3/carbon-based all-inorganic PSCs vs storage time during temperature cycles (between −22 and 100 °C) in a high-humidity ambient environment (90−95% RH, 25 °C) without encapsulation. Figure 4. (a) J−V plots of an all-inorganic PSC with a large active area of 1.0 cm measured in the forward and reverse scanning modes. (b) IPCE spectrum and integrated current density of the PSC in (a). Addition/Correction

Interface Engineering of Anchored Ultrathin TiO2/MoS2 Heterolayers for Highly-Efficient Electrochemical Hydrogen Production

An efficient self-standing hydrogen evolution electrode was prepared by in situ growth of stacked ultrathin TiO2/MoS2 heterolayers on carbon paper (CP@TiO2@MoS2). Owing to the high overall conductivity, large electrochemical surface area and abundant active sites, this novel electrode exhibits an excellent performance for hydrogen evolution reaction (HER). Remarkably, the composite electrode shows a low Tafel slope of 41.7 mV/dec, and an ultrahigh cathodic current density of 550 mA/cm2 at a very low overpotential of 0.25 V. This work presents a new universal strategy for the construction of effective, durable, scalable, and inexpensive electrodes that can be extended to other electrocatalytic systems.

Integrated perovskite solar capacitors with high energy conversion efficiency and fast photo-charging rate

Integrating energy harvesting devices with energy storage systems can realize a temporal buffer for local power generation and power consumption. In this manner, self-charging energy devices consisting of photovoltaic cells and energy storage units can serve as sustainable and portable distributed power sources that can concurrently generate and store electric energy without the need for external charging circuits. Herein, an integrated perovskite solar capacitor (IPSC) was realized by combining a perovskite solar cell (PSC) and a supercapacitor in a single device. Taking advantages of nanocarbon electrodes, the IPSCs possess a simple configuration, compact structure, and well-matched operation voltage. The IPSCs could be rapidly charged by different modes (including the photo-charging mode, galvanostatic-charging mode, and photoassisted-galvanostatic-charging mode), and showed a remarkable overall photo-chemical-electricity energy conversion efficiency as high as 7.1% in the photo-charging mode. Moreover, the IPSCs could work efficiently under weak light illumination. This study provides new insights for the design of novel integrative energy devices that combine the functions of solar power harvesting and electrochemical energy storage.

Highly Branched VS4 Nanodendrites with 1D Atomic-Chain Structure as a Promising Cathode Material for Long-Cycling Magnesium Batteries

Rechargeable magnesium batteries have attracted increasing attention due to the high theoretical volumetric capacities, dendrite formation-free characteristic and low cost of Mg metal anodes. However, the development of magnesium batteries is seriously hindered by the lack of capable cathode materials with long cycling life and fast solid-state diffusion kinetics for highly-polarized divalent Mg2+ ions. Herein, vanadium tetrasulfide (VS4 ) with special one-dimensional atomic-chain structure is reported to be able to serve as a favorable cathode material for high-performance magnesium batteries. Through a surfactant-assisted solution-phase process, sea-urchin-like VS4 nanodendrites are controllably prepared. Benefiting from the chain-like crystalline structure of VS4 , the S22- dimers in the VS4 nanodendrites provide abundant sites for Mg2+ insertion. Moreover, the VS4 atomic-chains bonded by weak van der Waals forces are beneficial to the diffusion kinetics of Mg2+ ions inside the open channels of VS4 . Through a series of systematic ex situ characterizations and density functional theory calculations, the magnesiation/demagnesiation mechanism of VS4 are elucidated. The VS4 nanodendrites present remarkable performance for Mg2+ storage among existing cathode materials, exhibiting a remarkable initial discharge capacity of 251 mAh g-1 at 100 mA g-1 and an impressive long-term cyclability at large current density of 500 mA g-1 (74 mAh g-1 after 800 cycles).