promise for low-cost solution processability. [1][2][3][4] Perovskite solar cells have experienced tremendous development in the past few years with power conversion efficiency (PCE) rapidly increased to over 20%. [5,6] Besides efficiency, another critical factor for practical application of perovskite solar cells is stability.Recently, Ruddlesden-Popper perovskites (RPPs) have been reported to have promising stability. [7][8][9] The RPPs can be structurally derived from their 3D counterparts with alternating organic ammonium layers and perovskite layers, giving the general formula of (RNH 3 ) 2 A n−1 M n X 3n+1 , where n represents the number of perovskite layers, RNH 3 is the organic spacer, and the A (small cation), M (divalent metal cation), and X (halide anion) form the perovskite framework. [10,11] The superior stability of RPPs can be attributed to the hydrophobic property of the organic spacer, which inhibits water molecules from penetrating and attacking the inorganic layers.Previous studies reported that RPPs exhibit enhanced stability but at the cost of reduced efficiency due to lower Recently, Ruddlesden-Popper perovskites (RPPs) have attracted increasing interests due to their promising stability. However, the efficiency of solar cells based on RPPs is much lower than that based on 3D perovskites, mainly attributed to their poor charge transport. Herein, a simple yet universal method for controlling the quality of RPP films by a synergistic effect of two additives in the precursor solution is presented. RPP films achieved by this method show (a) high quality with uniform morphology, enhanced crystallinity, and reduced density of sub-bandgap states, (b) vertically oriented perovskite frameworks that facilitate efficient charge transport, and (c) type-II band alignment that favors self-driven charge separation. Consequently, a hysteresis-free RPP solar cell with a power conversion efficiency exceeding 12%, which is much higher than that of the control device (1.5%), is achieved. The findings will spur new developments in the fabrication of high-quality, aligned, and graded RPP films essential for realizing efficient and stable perovskite solar cells. Solar CellsOrganic-inorganic halide perovskites, such as MAPbI 3 (MA = CH 3 NH 3 ), FAPbI 3 (FA = CH(NH 2 ) 2 ), and their mixed cation analogues, have emerged as promising light absorbers for solar cells due to their superior photophysical properties and

A high-performance hybrid white organic light-emitting device (WOLED) is demonstrated based on an efficient novel thermally activated delayed fluorescence (TADF) blue exciplex system. This device shows a low turn-on voltage of 2.5 V and maximum forward-viewing external quantum efficiency of 25.5%, which opens a new avenue for achieving high-performance hybrid WOLEDs with simple structures.

Interfacial reactions between the perovskite emitters and the interlayers are detrimental to the operational stability of the perovskite light-emitting diodes. Incorporating dicarboxylic acids into the precursor efficiently eliminates reactive organic ingredients in the perovskite emitters through an in situ amidation process, which is catalyzed by the alkaline zinc oxide substrate underneath. The formed amides improve the stability of the perovskite emitters and the charge injection contacts, ensuing notably improved operational stability of the resulting perovskite light-emitting diodes.

A composite of pyrite FeS2 microspheres wrapped by reduced graphene oxide (FeS2/rGO) has been synthesized by a facile one-step solvothermal method and applied as an anode in lithium ion batteries (LIBs).

We show the effects of chlorine incorporation in the crystallization process of perovskite film based on a lead acetate precursor. We demonstrate a fabrication process for fast grain growth with highly preferred {110} orientation upon only 5 min of annealing at 100 °C. By studying the correlation between precursor composition and morphology, the growth dynamic of perovskite film in the current system is discussed. In particular, we found that both lead acetate precursor and Cl incorporation are beneficial to perovskite growth. While lead acetate allows fast crystallization process, Cl improves perovskite crystallinity. Planar perovskite solar cells with optimized parameters deliver a best power conversion efficiency of 15.0% and average efficiency of 14.0% with remarkable reproducibility and good stability.

Room-temperature spin-based electronics is the vision of spintronics. Presently, there are few suitable material systems. Herein, we reveal that solution-processed mixed-phase Ruddlesden–Popper perovskite thin-films transcend the challenges of phonon momentum-scattering that limits spin-transfer in conventional semiconductors. This highly disordered system exhibits a remarkable efficient ultrafast funneling of photoexcited spin-polarized excitons from two-dimensional (2D) to three-dimensional (3D) phases at room temperature. We attribute this efficient exciton relaxation pathway towards the lower energy states to originate from the energy transfer mediated by intermediate states. This process bypasses the omnipresent phonon momentum-scattering in typical semiconductors with stringent band dispersion, which causes the loss of spin information during thermalization. Film engineering using graded 2D/3D perovskites allows unidirectional out-of-plane spin-funneling over a thickness of ~600 nm. Our findings reveal an intriguing family of solution-processed perovskites with extraordinary spin-preserving energy transport properties that could reinvigorate the concepts of spin-information transfer.

Despite the advanced progress in power conversion efficiency (PCE), developing air‐processed high‐efficiency perovskite solar cells (PVSCs) for future commercialization is still challenging. Here, we report that besides the general wisdom of the effect of moisture, oxygen in air has a severe impact on the quality of the solution‐deposited perovskite films. Interestingly, as opposed to moisture that induces fast crystallization of PbI2 upon deposition, oxygen exacerbates the wettability of the PbI2 solution on the substrates. We find that simply preheating the substrate and PbI2 solution a fully covered and uniform PbI2 film deposited in air can be obtained. This is possibly due to the increased vapor pressure of the solvent at higher temperatures to reduce the ingress of oxygen and moisture during the PbI2 deposition. Using this simple method, an air‐processed PVSC made under a humid atmosphere of 70% RH has a record PCE of 18.11%. Our work not only reveals the origin of the detrimental effects on perovskite film formation in ambient air, but also provides a simple practical strategy to develop air‐processed high‐efficiency PVSCs for future commercialization.

Human herpesvirus 6 (HHV-6) is an important immunosuppressive and immunomodulatory virus that primarily infects immune cells and strongly suppresses the proliferation of infected cells. However, the mechanisms responsible for the regulation and suppression mediated by HHV-6 are still unknown. In this study, we examined the ability of HHV-6A to manipulate cell cycle progression in infected cells and explored the potential molecular mechanisms. We demonstrated that infection with HHV-6A imposed a growth-inhibitory effect on HSB-2 cells by inducing cell cycle arrest at the G 2 /M phase. We then showed that the activity of the Cdc2-cyclin B1 complex was significantly decreased in HHV-6A-infected HSB-2 cells. Furthermore, we found that inactivation of Cdc2-cyclin B1 in HHV-6A-infected cells occurred through the inhibitory Tyr15 phosphorylation resulting from elevated Wee1 expression and inactivated Cdc25C. The reduction of Cdc2-cyclin B1 activity in HHV-6-infected cells was also partly due to the increased expression of the cell cycleregulatory molecule p21 in a p53-dependent manner. In addition, HHV-6A infection activated the DNA damage checkpoint kinases Chk2 and Chk1. Our data suggest that HHV-6A infection induces G 2 /M arrest in infected T cells via various molecular regulatory mechanisms. These results further demonstrate the potential mechanisms involved in immune suppression and modulation mediated by HHV-6 infection, and they provide new insights relevant to the development of novel vaccines and immunotherapeutic approaches.