In-cell optical sensing displays are essential for next-generation interactive electronics, yet conventional architectures rely on separate light-emitting diodes (LEDs) and photodetectors (PDs), limiting pixel density and efficiency. Achieving both functions within a single diode is intrinsically difficult because electroluminescence requires strong excitonic recombination, whereas photodetection benefits from efficient carrier separation. Here, we realize stable dual-mode operation by stabilizing intermediate-n quasi-2D phases and suppressing non-radiative losses with a fluorinated acid passivator, and by engineering high-mobility transport layers with a dissociative (type-II) perovskite/electron transport layer heterojunction to assist exciton dissociation under photovoltaic operation. The resulting bifunctional diode enables an opto-dynamic random-access memory (opto-DRAM) pixel, a two-transistor-one-diode (2T1D) architecture conceptually analogous to a two-transistor-one-capacitor (2T1C) DRAM gain-cell, where photovoltage-driven rather than photocurrent-driven detection enables self-amplified sensing when coupled to thin-film transistors. The sky-blue PeLED achieves an external quantum efficiency of 20.4% at 100 cd m-2 and a record power efficiency of 41.8 lm W-1, while as the coupled sensing pixel it exhibits a maximum responsivity of 4.17 × 104 A W-1 and a specific detectivity of 6.46 × 1013 Jones. Monolithic integration yields an active-matrix display capable of switchable emission and imaging functions offering a scalable platform for compact, energy-efficient, and multifunctional optoelectronics.

Abstract Stacking engineering in van der Waals heterostructures offers a powerful route to modulating band alignment and carrier dynamics. Here, we present a theoretical investigation of SiH/GeH van der Waals heterostructures with different stacking configurations. Distinct stacking-dependent band alignments are identified, with the most stable stacking exhibiting a Type-I alignment and the others adopting Type-II alignments. Time-dependent density functional theory combined with regional natural hole/particle orbital analysis demonstrates that strong interlayer coupling between conduction bands enables photoinduced interlayer charge-transfer excitations even in the Type-I alignment. Nonadiabatic molecular dynamics simulations further uncover a pronounced asymmetry between photoelectron and -hole dynamics, leading to ultrafast electron transfer (∼0.5 ps) and long-lived hole localization (∼20 ps). These results reveal a functional charge-separation mechanism in Type-I heterostructures and establish stacking engineering for controlling excited-state dynamics.

Semiconductors have shown growing promise for photocatalytic reactions due to their tunable band structures and efficient charge separation capabilities. Among them, metal halide perovskites (MHPs) have emerged as particularly attractive candidates owing to their intense light absorption and favorable charge transport properties; yet inefficient charge utilization often occurs in MHP-based photocatalysis due to undesired interfacial charge losses and lattice mismatches within the heterostructures. Herein, we report a two-dimensional perovskite (TMHP) photocatalyst, where selenol-functionalized organic cations are integrated into the lattice as both structural components and catalytic sites. This design enables efficient photoinduced charge separation and transfer from the [PbI4]2- layers to the selenol groups, achieving visible-light-driven reduction of α,β-unsaturated ketones with up to 87% yield across diverse substrates. Mechanistic studies reveal a radical-mediated pathway facilitated by the polarized lattice environment. This work demonstrates a new strategy for engineering molecular functionality into semiconductor lattices and creating integrated, efficient photocatalytic systems.

Plasmonic nanoparticles (NPs) enable exceptional light harvesting via localized surface plasmon resonances (LSPR), yet their photocatalytic utility is limited by ultrafast charge recombination and surface contamination from synthesis. Here, we overcome these challenges by applying the surface chemistry of silicon nanocrystals (SiNCs) to synthesize hybrid nanostructures of uncoated silver nanoparticles (AgNPs). The alkyl-passivated SiNC surface acts as a reductive template, guiding the in-situ formation of clean, interfacially coupled AgNPs while protecting the SiNC core from oxidation. This tailored architecture leverages a synegiestic mechanism to enhance AgNP plasmon resonance, drive efficient hot-electron transfer and improve charge carrier separation. The resulting Ag@SiNC hybrid achieves improved CO2 reduction performance, with a CO yield of 1,552 μmol/g and near 100% selectivity under visible light irradiation. This work establishes surface-engineered SiNCs as a versatile platform for designing high-performance plasmonic–semiconductor photocatalysts.

Controlled formation of silicon-silicon (Si-Si) bonds is essential for advancing silicon-based materials, but existing synthetic methods often require harsh conditions or metal catalysts. In a previous work, we accidentally found that Si-Si bond formation can be achieved via dehydrogenative coupling on hydride-terminated silicane (HSi), without the aforementioned harshness, in the presence of dimethyl sulfoxide (DMSO), a Lewis base (LB). Despite this serendipity, the general knowledge of how the structural and electronic properties of LBs affect the reaction efficiency remains unknown. Here, we address this gap by systematically investigating a broad range of LBs for this catalysis. Kinetic analysis reveals pronounced, structure-dependent variation in catalytic activity, modulated by the interplay of basicity, steric accessibility, and electronic stabilization of the intermediate. By integrating experimental kinetics with density functional theory (DFT) calculations, we identify the Si+(SiH3)3 affinity as a unified descriptor that quantifies the nucleophilic engagement of LBs in catalyzing Si-Si formation. This parameter correlates strongly with both calculated activation barriers and experimental performance across oxygen-, nitrogen-, and sulfur-based LBs, suggesting its potential utility as a guiding descriptor for catalyst design.

Recent advances in silicon and germanium nanocrystal surface chemistry and applications in energy storage and conversion are reviewed, emphasizing how tailored surface/ligand interactions dictate device performance.

The relationship between intrinsic electronic characteristics and functional properties is essential issue in design of perovskite photovoltaic materials. However, thermal stability, electronic structure and photovoltaic performance are often investigated independently, making it difficult to establish a unified electronic mechanism. In this work, the Empirical Electron Theory (EET) of Solids and Molecules is employed to investigate simultaneously these issues of CsGeX₃ (X = Cl, Br, and I) perovskites, and to predicted their cohesive energies, melting points, open-circuit voltage (Voc) and light absorption bandgap. These calculated properties are good agreement with the experimental data. The study reveals that these properties are simultaneously modulated by their valence electron structures (VES). The melting point and cohesive energy of CsGeX₃ strongly depends upon the covalence electron pairs on the strongest Ge-X bond and number of covalence electrons. Voc is governed by lattice electron counts and the valence electrons on CsI bond. The light absorption bandgap is modulated by the hybrid energy transition from low energy level to high one induced by light absorption. These findings reveal that VESs govern thermal stability, electronic and photovoltaic performance, providing insight into the design of cesium-based halide perovskites for photovoltaic applications.

The generation of interlayer charge transfer excitons upon photoexcitation is strongly desirable for two-dimensional (2D) materials stacked through van der Waals interactions. In this work, we investigate photoinduced charge transfer in silicanes (SiH) with three typical stackings. A concept of the regional natural hole orbital and its conjugated particle orbital is developed to characterize excited states in solids. This method delivers bonding information about excited states and explains the formation of certain types of states in nanomaterials. Utilizing this tool, we demonstrate that SiH in the 1H and 6R stackings exhibits an interlayer charge transfer distance that reaches ∼10 Å under violet and near-ultraviolet radiation. The charge transfer is attributed to the interlayer overlap between orbitals at the conduction band minimum, which is disfavored by the 3R stacking. Our findings suggest a new and feasible approach for tuning the optoelectronic properties of Group 14 2D materials by altering their stackings.

With the increasing global attention on energy and environmental issues, there is a growing push towards the eco-friendly transformation of adhesive materials. However, designing and developing eco-friendly adhesive materials with ultra-strong adhesion has always been a significant challenge in the field of adhesion. Herein, we present an eco-friendly adhesive (CBA) derived from bio-based thioctic acid (TA) that combines synergistic covalent and dynamic covalent polymeric segments, demonstrating strong adhesive strength and closed-loop recyclability. Specifically, leveraging the synergistic effects of dynamic covalent and covalent chain segments within the polymer network, the adhesive CBA exhibits ultra-strong adhesive strength (16.1 MPa), exceptional antifreeze performance (11.6 MPa at -196 degrees C), high reusability with 12.1 MPa retained after ten cycles, and resistance to common organic solvents. Importantly, the main chains of disulfide bonds formed through the solid-phase thermal-induced ring-opening polymerization of TA, combined with robust reversible amide bonds to crosslink into a network, enable closed-loop recyclability. This approach of using bio-based materials with synergistic dynamic covalent and covalent bonds effectively balances adhesive strength with environmental sustainability, offering an excellent solution for designing and developing new adhesive materials.

Two‐dimensional (2D) nanocrystals have recently risen to be highly promising for optoelectronics and microelectronics. However, it is a big challenge for 2D nanocrystals in the applications of long‐wavelength regions (e.g., ≥660 nm) and the development of 2D nanocrystal light‐emitting diodes (LEDs) with long‐wavelength emissions is in its infancy. Here, colloidal quantum‐well LEDs (CQW‐LEDs) with long‐wavelength emissions (671 nm) have been developed, simultaneously achieving high efficiency, extremely low efficiency roll‐off, high luminance, ultra‐saturated emission with CIE coordinates of (0.719, 0.280), and excellent color stability. The photoluminescence quantum yield of designed CdSe/CdZnS core/shell CQW films is as high as 92%. The resultant CQW‐LEDs exhibit an external quantum efficiency (EQE) of 17.45% and a luminance of 9335 cd m −2 , which are record values for 2D nanocrystal LEDs with long‐wavelength emissions. Experiments and simulations reveal that the high performance is attributed to the great enhancement of charge balance, which is fulfilled by the employment of effective triple hole transport layers. The strategy also enables red CQW‐LEDs to achieve an EQE of 20.41%. Such results provide a new approach to obtain CQW‐LEDs, pave the way to realize superior performance 2D nanocrystal LEDs with long‐wavelength emissions, and give a deep insight to regulate charge distribution for nanocrystal LEDs. image

The incorporation of tin (Sn) into crystalline silicon (c-Si) is challenging due to their substantial atomic size mismatch and the rigid diamond-type structure of c-Si. Herein, we demonstrate a solid-state synthetic approach of colloidal Sn-incorporated silicon nanocrystals with Sn content up to 0.12 atomic%. The incorporation of Sn atoms promotes silicon crystal growth, yielding NCs with increased size and enhanced crystallinity. The resulting particles exhibit intense near-infrared photoluminescence at 985 nm and demonstrate excellent thermal stability.

Colloidal germanium quantum dots (GeQDs) show great potential for optoelectronics, but traditional synthesis methods face challenges such as low yield and uneven particle sizes due to Ge sublimation and domain overgrowth at high temperatures. This study introduces a dopant-assisted synthesis method that enhances the crystallization process of GeQDs. By incorporating cobalt dopants into sol-gel precursors, we have effectively reduced the GeQD formation temperature to 350 °C. This approach boosts product yield over 60%, a 3.6-fold increase over conventional methods. The resulting GeQDs exhibit uniform particle sizes, enhanced solution processability, and improved charge carrier mobilities. We further constructed the GeQD-based solar cells that demonstrate an AM1.5 solar power conversion efficiency of 3.5 × 10-5% with a 0.83 V open-circuit voltage.

Perovskite materials have revolutionized optoelectronics by virtue of their tunable bandgaps, exceptional optoelectronic properties, and structural flexibility. Notably, the state-of-the-art performance of perovskite solar cells has reached 27%, making perovskite materials a promising candidate for next-generation photovoltaic technology. Although numerous reviews regarding perovskite materials have been published, the existing reviews generally focus on individual material systems (e.g., organic-inorganic hybrid perovskites) and specific optimizations in one particular optoelectronic application (e.g., stability engineering for solar cells), lacking a systematic overview of the progress and challenges across diverse perovskite types. This review breaks this limitation by providing a systematic overview of all perovskite categories used in solar cells classified by different criteria, including composition (organic-inorganic hybrid perovskites, all-inorganic perovskites, lead-free perovskites, and metal-free perovskites), dimensionality (3D and low-dimensional perovskitoids), and crystallinity (poly-crystal thin film and single-crystal perovskites). The recent progress and future perspectives for each category of perovskite solar cells are focused on, aiming to establish a holistic roadmap for perovskite solar cells toward technological innovations and industrial viability.

Ag2Te colloidal quantum dots (CQDs) with superior optoelectronic properties are promising candidates for shortwave infrared photodetectors. Their performance, however, is influenced by their size distribution and structural quality. The most widely used method for synthesizing Ag2Te CQDs employs phosphine-tellurium as a precursor. Phosphine, however, is suspected to affect the film's electrical conductivity, thereby rendering device performance. Recently, a phosphine-free synthesis approach for Ag2Te CQDs has been developed. This method requires continuous injection and growth routes to achieve absorption peaks greater than 1600 nm, and the surface passivation needs further refinement. To address these challenges, we propose a zinc halide (ZnX2)-controlled method that reduces precursor reactivity by forming complexes of Ag-X. This facilitates the growth of uniformly sized CQDs through a one-step hot injection process, resulting in nearly monodispersed CQDs with tunable optical bandgaps from 1.22 to 0.60 eV. This method also improves surface passivation due to Zn2 + incorporation in synthesis. Utilizing these Ag2Te CQDs, we fabricated infrared photodetectors that demonstrate a responsivity of 0.38 A W-1 and an external quantum efficiency of 30 % at 1550 nm, positioning them among the best-performing CQD photodetectors.

Two-dimensional (2D) silicanes are promising semiconductors for applications in optoelectronics and photochemistry. Covalent functionalization presents a facile strategy to customize silicanes to attain desired properties. A comprehensive understanding of the impacts of ligands on silicanes is thus pivotal. In this study, we perform density functional theory (DFT) and time-dependent DFT (TDDFT) calculations to investigate the effects of three typical classes of ligands: (1) sigma-withdrawing and pi-donating, (2) sigma-withdrawing and pi-withdrawing, and (3) sigma-donating and pi-withdrawing, on the geometric structure, electronic structure, and band edge excited states of silicanes. Covalent functionalization of silicanes enables a wide range of band edge energies. The band gaps can be tuned between indirect and direct, and the underlying mechanism is explained for the first time. Additionally, TDDFT calculations confirm that the band edge optical absorptions can be adjusted by the ligands broadly from the near-infrared to the visible light region. These desirable properties enhance the functionalities of silicanes. Methodologically, we discuss the applicability of using the conventional one-particle orbital model to describe the excited states of silicanes, and nail down the similar to 0.1 eV inaccuracy of the model in describing excited state splittings. We present empirical functions for quick estimations of band edge energies of covalently functionalized silicanes. Through careful comparisons, we justify the use of the carbon-adapted sigma/pi-donating/accepting indices of typical ligands in silicon chemistry and present a set of silicon-based indices for future prudent applications in inorganic computational studies of silicon-based materials.

Two-dimensional metal halide perovskites (TMHPs) have emerged as prominent semiconductor materials in optoelectronic devices due to their composition-dependent properties. While previous research has concentrated on the types and the lengths of cations affecting TMHPs, our study systematically explores a new series of Dion-Jacobson (DJ)-phase TMHP structures featuring dithioketal-containing organic cations. Through X-ray crystallography and spectroscopy analyses, we demonstrate that steric hindrance from longer-branched groups distorts the structures and influences the photophysical behaviors of TMHPs. Additionally, we observe thermodynamically driven transitions from the DJ phase to the Ruddlesden-Popper (RP) phase when incorporating cations with extended branches, further impacting their structural and optoelectronic characteristics. Understanding and controlling these structural changes enable the design of TMHPs with tailored properties, opening avenues for advanced materials that enhance device performance.

Compared to organic-inorganic hybrid perovskite solar cells (PSCs), all inorganic CsPbBr3 perovskite solar cells have higher stability but lower efficiency. Owing to the low solid solubility of CsBr in methyl alcohol, an incomplete first-step reaction with PbBr2 reaction takes place at room temperature. As a result, a large amount of CsPb2Br5 is generated in the final CsPbBr3 film, which deteriorates the performance of CsPbBr3 PSCs. Along these lines, in this work, CsCl was added to increase the reaction between CsBr and PbBr2 in the first step and high-quality CsPbBr3 films were prepared without CsPb2Br5. Our analysis demonstrated that at the optimal CsCl concentration of 6% in CsBr solution, the CsPbBr3 perovskite solar cells exhibited a power conversion efficiency of 7.33%. The best device retained 98.57% of the power conversion efficiency (PCE) after storing it for 30 days under ambient air condition.

Controlling the reaction rates between precursors and doping agents is an effective strategy for state-of-the-art perovskite solar cells (PSCs). In our research study, ammonium bromide (NH4Br) was incorporated into a methylammonium iodide (MAI) precursor solution using a conventional two-step spin-coating technique, which resulted in a notable improvement in the performance of nanorod-based PSCs. Our findings indicate that adding NH4Br results in a perovskite film free of PbI2 residue, with an average grain size surpassing 1 mu m. This effect is likely attributed to NH4+, which regulates the reaction dynamics between MAI and PbI2. Furthermore, during the crystallization process, Br- partially replaces I- in the MAPbI3 lattice, causing lattice contraction that enhances the open-circuit voltage. Photovoltaic testing revealed that as the concentration of NH4Br increased, the cell efficiency initially improved, reaching a peak before declining. Significantly, when the NH4Br concentration reached 12 mg ml-1, the device attained a maximum power conversion efficiency (PCE) of 19.07%, marking an impressive 26.8% enhancement compared to devices without NH4Br.

The surface modification of hydride-terminated silicane (HSi) via thermal alkoxylation is experimentally demonstrated for the first time. Using two types of alcohol (butanol and dodecanol), alkoxyl groups are successfully grafted onto HSi through a mild thermal process, preserving the two-dimensional (2D) structure of HSi. Spectroscopic characterization confirms the formation of Si-O linkages, and electron microscopy reveals intact morphologies of alkoxylized silicane. These alkoxylated silicanes exhibit a distinct blue shift in photoluminescence (PL) emission and significantly faster PL decays compared to those of pristine HSi. Temperature-dependent PL measurements and density functional theory calculations reveal that the green emission of HSi arises from radiative recombination at an indirect band gap, whereas the blue emission of alkoxy-terminated silicane originates from surface trap states introduced by alkoxylation.

The optoelectronic tunability and solution processability of colloidal germanium quantum dots (GeQDs) make them highly attractive as active materials for thin film optoelectronics. However, while long-chain aliphatic ligands can effectively protect GeQD surfaces from oxidation and enhance colloidal stability, their insulating nature severely impedes charge carrier transport within the GeQD active layer. In this study, we introduce a solid-state ligand exchange (SSLE) approach using methylammonium iodide (MAI) to replace the insulating oleylamine ligands, thereby enhancing charge carrier mobilities in the GeQD thin film. We demonstrate that a low concentration of MAI effectively substitutes for OAm on GeQD surfaces while preserving the structural integrity of the crystalline core. The resulting MAI-passivated GeQD films exhibit significantly reduced trap densities and enhanced hole and electron mobilities compared with their OAm-passivated counterparts. Furthermore, we fabricate solar cells using a layer-by-layer SSLE process to construct a multilayered GeQD active layer, achieving a power conversion efficiency of up to 1.64 x 10-3 %, a significant improvement over previously reported GeQD photovoltaics.