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Ionic‐conductive solid‐state polymer electrolytes are promising for the development of advanced lithium batteries yet a deeper understanding of their underlying ion‐transfer mechanism is needed to improve performance. Here we demonstrate the low‐enthalpy and high‐entropy (LEHE) electrolytes can intrinsically generate remarkably free ions and high mobility, enabling them to efficiently drive lithium‐ion storage. The LEHE electrolytes are constructed on the basis of introducing CsPbI3 perovskite quantum dots (PQDs) to strengthen PEO@LiTFSI complexes. An extremely stable cycling >1000 h at 0.3 mA cm−2 can be delivered by LEHE electrolytes. Also, the as‐developed Li | LEHE | LiFePO4 cell retains 92.3% of the initial capacity (160.7 mAh g−1) after 200 cycles. This cycling stability is ascribed to the suppressed charge concentration gradient leading to free lithium dendrites. It is realized by a dramatic increment in lithium‐ion transference number (0.57 vs 0.19) and a significant decline in ion‐transfer activation energy (0.14 eV vs 0.22 eV) for LEHE electrolytes comparing with PEO@LiTFSI counterpart. The CsPbI3 PQDs promote highly structural disorder by inhibiting crystallization and hence endow polymer electrolytes with low melting enthalpy and high structural entropy, which in turn facilitate long‐term cycling stability and excellent rate‐capability of lithium‐metal batteries. [ABSTRACT FROM AUTHOR]

Controllable crystallization growth of perovskite films with excellent morphology and outstanding properties is a key and intractable problem for efficient and stable perovskite optoelectronic devices. However, the inhomogeneous inherent defects at the grain boundaries and interfaces make it difficult to uniformly release the residual stress during the growth process of perovskite films. Here, a molecular needle knitting strategy with dimethyl sulfoxide solvent as needles and polyoxyethylene molecular chains as threads was proposed to reveal the growth mechanism of perovskite–polymer composite films. Owing to the knitted net-structured cages synergistically constructed by the molecular needles and threads, the perovskite precursors can be uniformly assigned to each cage and nucleated evenly for the effective residual stress release under the formed spatial confinement effect. Compared with no confined cages, this obtained CsPbBr3 film via the molecular needle knitting strategy showed 50% enhanced photoluminescence quantum yield together with 40% improved stabilities. Based on this CsPbBr3 film and an UV LED chip (365 nm), we fabricated a high-stability and pure green LED lamp (528 nm). This work may open a way to achieve high quality fluorescent perovskite films and further extend their practical application in lighting and display fields. [ABSTRACT FROM AUTHOR]

Suppressing the naturally ultrafast nucleation and growth rates of perovskite nanocrystals is a big challenge to develop high‐performance deeply blue perovskite light‐emitting diodes. Here, a cryogenic temperature thermodynamically suppressed synthetic strategy using liquid nitrogen is designed to obtain ultrasmall CsPbBr3 quantum dots (QDs; ≈3 nm). Due to its strong confinement effect, the as‐obtained CsPbBr3 QDs present strong deeply blue emission (≈460 nm) with a high quantum yield value of up to 98%, a large exciton binding energy of 301.6 meV, and excellent spectra stability for 60 d under atmosphere environment. This unprecedented regime indicates that cryogenic temperature can eliminate pre‐existing trap states and suppress the nonradiative process. Besides, the resultant perovskite light‐emitting diodes based on ultrasmall CsPbBr3 QDs show deeply blue emission (≈ 460 nm) with a Commission Internationale de l'Eclairage (CIE) color coordinate of (0.145, 0.054), better than the blue National Television Standards Committee (NTSC) standard. Evidently, this cryogenic temperature synthetic strategy will pave the way for the large‐scale synthesis of the strongly confined ultrasmall quantum dots systems and open the door for the development of next generation solid‐state lighting and displays. [ABSTRACT FROM AUTHOR]

Nontoxic self-powered ZnO-based photodetectors are highly desired to meet the great demand for sensing, communication, and imaging applications, while directionally manipulating the confined photocarrier transport is critical to the enhancement in the photodetection performance. Herein, we demonstrated a highly c-axis-oriented Cu2ZnSnS4/ZnO (CZTS/ZnO) photodetector with coaxially enhanced photocarrier transport. This CZTS/ZnO photodetector delivers remarkable 31 times higher photocurrent mainly ascribed to the coaxially enhanced photocarrier transport in the vertically directed ZnO arrays through the nanoconfinement effect along with the substantially enhanced incident photon absorption of length-optimized ZnO nanorods (NRs). Furthermore, this photodetector delivers a high responsivity of 1.1 μA W−1, fast rise time of 600 ms, and decay time of 600 ms as well as good stability with no distinct photocurrent decay after 2500 cycles. This study will open up a coaxially enhanced photocarrier transport way to substantially improve the photodetection performance and may promote the development of next-generation optoelectronic devices. [ABSTRACT FROM AUTHOR]