Charge Carrier Lifetime Research Articles

Fabrication and Characterization of a Lead-Free Cesium Bismuth Iodide Perovskite through Antisolvent-Assisted Crystallization.

Cesium bismuth iodide perovskite material offers good stability toward ambient conditions and has potential optoelectronic characteristics. However, wide bandgap, absorber surface roughness, and poor surface coverage with pinholes are among the key impediments to its adoption as a photovoltaic absorber material. Herein, bandgap modification and the tailoring of surface morphology have been performed through molar ratio variation and antisolvent treatment, whereby type III antisolvent (toluene) based on Hansen space has been utilized. XRD and Raman spectroscopy analyses confirm the formation of a 0D/2D mixed dimensional structure with improved optoelectronic properties when the molar ratio of CsI/BiI3 was adjusted from 1.5:1 to 1:1.5. The absorption results and Tauc plot determination show that the fabricated film has a lower bandgap of 1.80 eV. TRPL analysis reveals that the film possesses a very low charge carrier lifetime of 0.94 ns, suggesting deep defects. Toluene improves the charge carrier lifetime to 1.89 ns. The average grain size also increases from 323.26 nm to 444.3 nm upon toluene addition. Additionally, the inclusion of toluene results in a modest improvement in PCE, from 0.23% to 0.33%.

Size‐Dependent Multi‐Electron Donation in Metal‐Complex Quantum Dots Hybrid Catalyst for Photocatalytic Carbon Dioxide Reduction

AbstractThe effective conversion of carbon dioxide (CO2) into valuable chemical fuels relies significantly on the donation of multiple electrons. Its efficiency is closely linked to both the density and lifetime of excited charge carriers. In this study, a hybrid catalyst system comprising covalently bonded InP/ZnS quantum dots (QDs) and Re‐complexes is showcased. The electronic band alignment between the QDs and the Re‐complexes is revealed to dominate the multi‐electron transfer process for photocatalytic conversion to methane (CH4). Notably, the size of the QDs is found to be a determining parameter. Among the three QD sizes investigated, transient absorption spectroscopy studies unveil that rapid multi‐electron transfer from the QDs to the Re‐catalyst occurs in smaller QDs (2.3 nm) due to the substantial driving force. Consequently, the photocatalytic conversion of CO2 to CH4 is significantly enhanced with a turnover number of 6, corresponding to the overall apparent quantum yield of ≈1%. This research underscores the possibilities of engineering multi‐electron transfer by manipulating the electronic band alignment within a catalytic system. This can serve as a guide for optimizing photocatalytic CO2 reduction.

Efficient visible light-driven photodegradation of glyphosate utilizing Bi2WO6 with oxygen vacancies: Performance, mechanism, and toxicity assessment

Global environmental deterioration poses a major risk to ecological security and human health, and emerging technologies are urgently needed to deal with it. Therefore, the exploitation of photocatalysts with favorable activity for efficient degradation of pesticide contaminants is one of the strategies to achieve environmental remediation. Herein, oxygen vacancy-rich Bi2WO6 (Ov-BWO) was prepared through a solvothermal method utilizing ethylene glycol (EG), which exhibited excellent photocatalytic efficiency in photodegradation of glyphosate. The formation of oxygen vacancies (Ovs) in Ov-BWO was demonstrated utilizing XPS and EPR. PL, TRPL, photocurrent tests, and EIS analyses revealed that Ovs accelerated effective transfer of photogenerated charge, extended lifetime of charge carriers, promoted production of active species and significantly improved the photocatalytic performance. Compared with the low-activity Bi2WO6 (BWO, 59.6%), Ov-BWO showed outstanding photocatalytic activity, achieving a degradation efficiency of 91% for glyphosate at 120 min of visible light irradiation. Moreover, Ov-BWO also displayed outstanding recyclable stability after four repeated uses. Based on the characterization of photoelectric properties, a feasible photocatalytic reaction was put forth, along with glyphosate degradation pathways. Furthermore, the degradation intermediates of glyphosate were analyzed in detail employing HPLC-MS. The toxicity assessment indicated that degraded products had been proven to be non-toxic to the ecological system. This work presents the potential of photocatalysts with Ovs for the photodegradation of pesticides, providing a viable strategy for environmental renovation.

Ultrasound Induces Local Disorder of FeOOH on CdIn2S4 Photoanode for High Efficiency Photoelectrochemical Water Oxidation.

The regulation of the crystal structure of oxygen evolution cocatalyst (OEC) is a promising strategy for enhancing the photoelectrochemical efficiency of photoanodes. However, the prevailing regulating approach typically requires a multistep procedure, presenting a significant challenge for maintaining the structural integrity and performance of the photoanode. Herein, FeOOH with a local disordered structure is directly grown on a CdIn2S4 (CIS) photoanode via a simple and mild sonochemical approach. By modulating the localized supersaturation of Ni ions, ultrasonic cavitation induces Ni ions to participate in the nucleation and growth of FeOOH clusters to cause local disorder of FeOOH. Consequently, the local disordered FeOOH facilitates the exposure of additional active sites, boosting OER kinetics and extending charge carrier lifetimes. Finally, the optimal photoanode reaches 4.52mAcm-2 at 1.23VRHE, and the onset potential shifts negatively by 330mV, exhibiting excellent performance compared with that of other metal sulfide-based photoelectrodes reported thus far. This work provides a mild and controllable sonochemical method for regulating the phase structure of OECs to construct high-performance photoanodes.

Collaborative Management of Light‐Absorbing Supplementation and Defect Passivation Based on Green‐Emitting ((CH3)4N)2(C2H5)4N·MnBr4 Single Crystals for Efficient and Stable Inverted Perovskite Solar Cells

In conventional p–i–n inverted perovskite solar cells (PSCs), there exists considerable energy loss due to both unsatisfactory light path design and trap‐induced interfacial defects. The sunlight is absorbed competitively by conductive oxide substrates and hole transport material in front of the perovskite layer, while the opaque metal back electrode also prevents light penetration. Worse yet, there is severe nonradiative charge recombination caused by defects between the perovskite layer and the electron transport material. To tackle the above two issues, a new green‐emitting material ((CH3)4 N)2(C2H5)4N·MnBr4 is synthesized and introduced in/on the perovskite layer to achieve both defect passivation and light complementation. The green luminescence of this single crystal at the interface is found to provide secondary light absorption, as evidenced by a remarkable promotion of short‐circuit current density. It is also found that the excess PbI2 on the surface of perovskite can be effectively removed, and as the interfacial additive, ((CH3)4 N)2(C2H5)4 N·MnBr4 inhibits trap‐assisted recombination losses, which provides favorable energy‐level alignment and extends charge carrier lifetime. As a result, the champion PCE (21.23%) of the target‐treated ((CH3)4 N)2(C2H5)4 N·MnBr4 device exceeds that 19.5% of the pristine‐without ((CH3)4 N)2(C2H5)4 N·MnBr4 device. This work provides an effective interfacial strategy for high‐performance and stable inverted PSCs.

Transient-State Self-Bipolarized Organic Frameworks of Single Aromatic Units for Natural Sunlight-Driven Photosynthesis of H2O2.

Constructing π-conjugated polymer structures through covalent bonds dominates the design of organic framework photocatalysts, which significantly depends on the selection of multiple donor-acceptor building blocks to narrow the optical gap and increase the lifetimes of charge carriers. In this work, self-bipolarized organic frameworks of single aromatic units are demonstrated as novel broad-spectrum-responsive photocatalysts for H2O2 production. The preparation of such photocatalysts is only to fix the aromatic units (such as 1,3,5-triphenylbenzene) with alkane linkers in 3D space. Self-bipolarized aromatic units can drive the H2O2 production from H2O and O2 under natural sunlight, wide pH ranges (3.0-10.0) and natural water sources. Moreover, it can be extended to catalyze the oxidative coupling of amines. Experimental and theoretical investigation demonstrate that such a strategy obeys the mechanism of through-space π-conjugation, where the closely face-to-face overlapped aromatic rings permit the electron and energy transfer through the large-area delocalization of the electron cloud under visible light irradiation. This work introduces a novel design concept for the development of organic photocatalysts, which will break the restriction of conventional through-band π-conjugation structure and will open a new way in the synthesis of organic photocatalysts.

Two Completely Non‐Fused Ring Acceptors Working in an Alloy‐Like Model for Efficient and Stable Organic Solar Cells

AbstractSimple chemical structure and simplified synthesis process of active layer materials are critical for advancing the practical application of organic solar cells. Herin, two completely non‐fused ring electron acceptors BTZT‐2Cl and BTZT‐4Cl are developed. BTZT‐4Cl exhibits an enhanced absorption band, increases electrostatic potential differences with D18, and improves crystallinity and molecular packing properties. Consequently, the binary device based on BTZT‐4Cl displays a markedly improved efficiency of 14.12%, compared to the BTZT‐2Cl‐based device, which only achieves a moderate efficiency of 11.25%. More importantly, an alloy‐like structure can be formed by incorporating a small amount of high miscibility and compatibility BTZT‐2Cl. The ternary blend exhibits more compact molecular packing, efficient exciton dissociation, and an extended charge carrier lifetime due to the formation of an alloy‐like structure. The ternary device achieves a decent efficiency of 15.41% with superior thermal stability and a high T80 lifetime over 1600 h after being aged at 65 °C. These results establish it as the most efficient among devices based on completely non‐fused ring acceptors with both high efficiency and voltage. This study demonstrates a simple material design strategy and high‐performance device optimization techniques, which are critical for advancing practical applications in the OSC field.

Space charge region recombination in highly efficient silicon solar cells

The recombination rate in the space charge region (SCR) of a silicon-based barrier structure with a long Shockley–Reed–Hall lifetime is calculated theoretically by taking into account the concentration gradient of excess electron-hole pairs in the base region. Effects of the SCR lifetime and applied voltage on the structure ideality factor have been analyzed. The ideality factor is significantly reduced by the concentration gradient of electron-hole pairs. This mechanism provides an increase of the effective lifetime compared to the case when it is insignificant, which is realized at sufficiently low pair concentrations. The theoretical results have been shown to be in agreement with experimental data. A method of finding the experimental recombination rate in SCR in highly efficient silicon solar cells (SCs) has been proposed and implemented. It has been shown that at the high excess carrier concentration exceeding 1015 cm–3 the contribution to the SCR recombination velocity from the initial region of SCR that became neutral is significant. From a comparison of theory with experiment, the SCR lifetime and the ratio of the hole to the electron capture cross sections are determined for a number of silicon SCs. The effect of SCR recombination on the key characteristics of highly efficient silicon SCs, such as photoconversion efficiency and open-circuit voltage, has been evaluated. It has been shown that they depend not only on the charge carrier lifetime in SCR, but also on the ratio of hole to electron capture cross sections σp /σn. When σp /σn < 1, this effect is significantly strengthened, while in the opposite case σp /σn > 1 it is weakened. It has been ascertained that in a number of highly efficient silicon SCs, the distribution of the inverse lifetime in SCR is described by the Gaussian one. The effect described in the paper is also significant for silicon diodes with a thin base, p-i-n structures, and for silicon transistors with p-n junctions. In Appendix 2, the need to take into account the lifetime of non-radiative excitonic Auger recombination with participation of deep impurities in silicon is analyzed in detail. It has been shown, in particular, that considering it enables to reconcile the theoretical and experimental dependences for the effective lifetime in the silicon bulk.

Science in 2025-2027 and the SPQEO journal

Relevance of recent research is important for scientists and journals reporting research results. There are many sources of prognoses and one of them is the Report of European Commission "Looking into the R&I future priorities 2025-2027". It predicts the importance of the following areas for users: healthcare, energy, climate, sustainability and digitalization. The Ukrainian journal Semiconductor Physics, Quantum Electronics and Optoelectronics (SPQEO) actually focuses on these areas and contributes to the development of related knowledge. Monitoring of last SPQEO issues shows some interesting results: (i) the effect of local field amplification, which causes emergence of ponder motive forces acting on viruses until destruction of viral envelopes; (ii) the methods of malignant tumors treatment taking into account their genesis mechanisms and focusing on correction of definite pathogenesis components, while being nontoxic for other organs and tissues; and (iii) manipulation of the spectral characteristics of a “polycarbonate matrix – gold nanostructures – HTTH dye” system due to influence of gold nanostructures. SPQEO paid attention to the improvement of solar cells (SCs) by considering physical effects such as the effect of space charge region (SCR) recombination on the key characteristics of high-efficiency silicon solar cells, such as photovoltaic conversion efficiency and open-circuit voltage, is not only dependent on the charge-carrier lifetime in the SCR, but also on the ratio of hole-to-electron-capture cross section, σp/σn. Non- traditional SCs were also considered: SCs with perovskite thin films, SCs comprising CdS/CIGS heterojunctions, and vitamin B12-patterned silicon hybrids based SCs. Moreover, SPQEO also covers research results in the fields of quantum devices, diamond- like and oxide films, and light-emitting diodes.

Enhanced photoelectrochemical water splitting via hydrogenated TiO2 nanotubes modified with Cu/CuO species

This study explores the collective influence of hydrogenation thermal treatment and the decoration of Cu/CuO onto TiO2 nanotubes (TiO2-NTs) concerning photoelectrochemical water splitting. To introduce point defects such as oxygen vacancies and Ti3+, electrochemically anodized Ti foils underwent hydrogenation in a 90 % Ar-10 % H2 atmosphere at 500 °C. Subsequently, Cu/CuO species were deposited on the hydrogenated TiO2-NTs through chemical decoration for varying stirring durations of 15, 30, 45, and 60 min. EPR analysis of the hydrogenated sample unveiled resonances at g-values distinct from the typical 1.997 signal associated with oxygen vacancies in TiO2-NTs, signifying the presence of Ti3+ and VO defects. Analysis via XPS identified Cu and CuO as the primary compositions of the decorated species on the hydrogenated TiO2-NTs. Additionally, SEM/EDS results showcased that longer stirring times, specifically 60 min., caused localized agglomeration of Cu/CuO species and TiO2-NTs breakage. The Cu/CuO-decorated hydrogenated TiO2-NTs exhibited enhanced absorption of visible light, leading to a band gap reduction to 2.09 eV after 45 min of Cu/CuO decoration. Notably, this particular sample demonstrated the highest photocurrent of 3.6 mA/cm2 and a photo-conversion efficiency of 2.48 % at 1.23 V vs. RHE. Overall, the presence of Cu/CuO species prolonged the lifetime of charge carriers, as evidenced by Nyquist plots and Mott-Schottky analysis. A schematic model is suggested based on the modified band gap of hydrogenated TiO2-NTs subsequent to Cu/CuO loading.

Fluorinated Quasi 2D Perovskite Solar Cells with Improved Stability and Over 19% Efficiency

Abstract2D Ruddlesden–Popper perovskites (RPP) with excellent environmental and structural stability are emerging photovoltaic materials. Here, a benzylamine‐based spacer, namely 3,5‐difluorobenzylamine (DF‐BZA), is developed for stable and efficient quasi‐2D‐RP perovskite solar cells (PSCs). Compared to benzylamine (BZA)‐based quasi‐2D RPP, the DF‐BZA‐based perovskite film exhibited superior film quality with significantly enlarged grain size and improved charge carrier lifetime owing to the fluorine atoms in DF‐BZA. As a result, the optimized (DF‐BZA)2FA3Pb4I13 PSCs achieve a power conversion efficiency (PCE) of 19.24%, while BZA‐based PSCs ((BZA)2FA3Pb4I13) only achieve a PCE of 17.04%. This represents the champion PCE using FA as the A‐site cation in quasi‐2D RPPs with n = 4. Moreover, due to the effective insertion of fluorinated spacers into the inorganic layers, the moisture resistance stability and 85 °C thermal stability of (DF‐BZA)2FA3Pb4I13 are significantly improved. The improvement of photovoltaic performance and stability highlight the great potential of DF‐BZA‐based spacer for high‐performance quasi‐2D RP PSCs.

Nuclear Quantum Effects Accelerate Charge Recombination but Boost the Stability of Inorganic Perovskites in Mild Humidity.

Experiments have demonstrated that mild humidity can enhance the stability of the CsPbBr3 perovskite, though the underlying mechanism remains unclear. Utilizing ab initio molecular dynamics, ring polymer molecular dynamics, and non-adiabatic molecular dynamics, our study reveals that nuclear quantum effects (NQEs) play a crucial role in stabilizing the lattice rigidity of the perovskite while simultaneously shortening the charge carrier lifetime. NQEs reduce the extent of geometric disorder and the number of atomic fluctuations, diminish the extent of hole localization, and thereby improve the electron-hole overlap and non-adiabatic coupling. Concurrently, these effects significantly suppress phonon modes and slow decoherence. As a result, these factors collectively accelerate charge recombination by a factor of 1.42 compared to that in scenarios excluding NQEs. The resulting sub-10 ns recombination time scales align remarkably well with experimental findings. This research offers novel insight into how moisture resistance impacts the stability and charge carrier lifetime in all-inorganic perovskites.

Fabrication and Characterization of Electrospun Cu-Doped TiO2 Nanofibers and Enhancement of Photocatalytic Performance Depending on Cu Content and Electron Beam Irradiation.

Titanium dioxide (TiO₂) is a widely studied material with many attractive properties such as its photocatalytic features. However, its commercial use is limited due to issues such as deactivation in the visible spectrum caused by its wide bandgap and the short lifetime of photo-excited charge carriers. To overcome these challenges, various modifications could be considered. In this study, we investigated copper doping and electron beam treatment. As-spun TiO2 nanofibers were fabricated by electrospinning a TiO2 sol, which obtained viscosity through a polyvinylpyrrolidone (PVP) matrix. Cu-doped TiO2 nanofibers with varying dopant concentrations were synthesized by adding copper salts. Then, the as-spun nanofibers were calcined for crystallization. To evaluate photocatalytic performance, a photodegradation test of methylene blue aqueous solution was performed for 6 h. Methylene blue concentration was measured over time using UV-Vis spectroscopy. The results showed that Cu doping at an appropriate concentration and electron-beam irradiation showed improved photocatalytic efficiency compared to bare TiO2 nanofibers. When the molar ratio of Cu/Ti was 0.05%, photodegradation rate was highest, which was 10.39% higher than that of bare TiO2. As a result of additional electron-beam treatment of this sample, photocatalytic efficiency improved up to 8.93% compared to samples without electron-beam treatment.

Oxygen vacancy induced carrier localization in enhancing photocatalytic performance of ZnO

Within the realm of advancing photocatalysis, the investigation of material defects has perennially commanded paramount attention. However, a nuanced comprehension of the intricate interplay between these defects and the catalytic milieu necessitates deeper exploration. In the present study, oxygen vacancies (Vo) were adeptly harnessed to induce precise carrier localization, thereby effectuating a heightened augmentation of photocatalytic activity. This augmentation was deftly achieved through the deliberate modulation of external illumination parameters, resulting in the extension of carrier lifetimes. Specifically, the drastically enhanced carrier effective mass (m*) and the density of unoccupied state are directly uncovered by the density functional theory (DFT) calculation and Raman spectra. Through the utilization of wavelength dispersive in-situ fluorescence spectroscopy (WDIFS) experiments, it was observed that Vo-rich ZnO nanoparticles (NPs) displayed noteworthy photocatalytic activity around the central frequency of Vo (5.17 × 1014 Hz, 580 nm), owing to the highly efficient utilization of localized carriers. Moreover, based on Einstein rate equations, the charge carrier lifetime was found to be further prolonged with increased external illumination intensity and excitation wavelength. This work provides a methodology for optimizing the functionality of point defect on photocatalysis, where the photo-induced charge carrier localization is expected to be extensively used in further photocatalysis research.

Overcoming Defect Limitations in Photocatalysis: Boron‐Incorporation Engineered Crystalline Red Phosphorus for Enhanced Hydrogen Production

AbstractPhotocatalytic hydrogen evolution (PHE) from water splitting is a promising technology for clean and renewable energy production. Elemental crystalline red phosphorus (CRP) is purposefully designed and developed for PHE reaction. However, the photocatalytic activity of CRP is limited by its intrinsic P vacancy (VP) defects, which lead to detrimental charge trapping at deep states and hence its severe recombination. To address this issue, a boron (B) incorporated CRP (B‐CRP) photocatalyst is tailored, synthesized via a simple and mild boric acid‐assisted hydrothermal strategy. The incorporation of B effectively fills the VP defects, reducing deep trap states (DTS) and introducing beneficial shallow trap states (STS) within the band structure of CRP. This defect engineering approach leads to enhanced photocatalytic activity, with B‐CRP achieving a PHE rate of 1392 µmol g−1 h−1, significantly outperforming most reported elemental photocatalysts in the literature. Density functional theory (DFT) simulations and ultrafast spectroscopy support the constructive role of B‐dopant‐induced STS in prolonging active charge carrier lifetimes, promoting more efficient photocatalytic reactions. The findings not only demonstrate the effectiveness of B‐CRP as a photocatalyst but also highlight the usefulness of dopant‐induced STS in advancing PHE technologies.

Investigation on the Long-Term Stability of AlOx/SiNy:H and SiNy:H Passivation Layers During Illuminated Annealing at Elevated Temperatures

Most crystalline Si based solar cells, e.g. passivated emitter and rear cells, rely on SiNy:H and AlOx/SiNy:H passivation layers. In this work, the long-term behavior of minority charge carrier lifetime in such symmetrically passivated samples during illuminated annealing at elevated temperatures is investigated by means of photoconductance decay based lifetime measurements, corona charging and capacitance voltage measurements. Thereby, AlOx layers, which are known to reduce H in-diffusion due to their barrier properties, deposited by atmospheric pressure chemical vapor deposition as well as by atomic layer deposition were considered enabling a comparison of different deposition techniques. The frequently published behavior of the bulk related degradation could be confirmed and the qualitative correlation between maximum defect density and the changing total amount of H in the Si bulk due to the barrier properties of the individual layers dielectric layers could be shown. Furthermore, for the subsequently observed degradation accelerated by a treatment at higher temperatures, literature indicates degradation to be caused by surface related degradation. Investigations on field effect passivation during degradation by means of corona charging and CV measurements showed a large drop in fixed negative charges in the passivation layer stacks.

Solution-processed asymmetry conjugated reticular oligomers for large-area panel photoelectrodes in photoelectrochemical devices

Covalent organic frameworks (COFs) show potential in photoelectrochemical (PEC) water reduction. Herein, we synthesize solution-processed benzoxazole-based conjugated reticular oligomers (BBO-CROs) in micelle nanoreactors, acting as an “electronic paint” for fabricating consecutive panel-type photoelectrodes for PEC water reduction. The small-molecule BBO-CROPDA, BBO-CRODHTA, and BBO-CROBPY exhibit a narrower energy bandgap and prolong the fluorescence lifetimes of photoinduced charge carriers compared to bulk BBO-COFs. Colloidal COFs in PEC water reduction are illustrated through the creation of flexible full devices via spinning coating. The optimized photoelectrode CuI/BBO-CROBPY+P27/SnO2/Pt result in ΔJ of 86.5 μA cm−2 at 0.4 V vs. RHE, which is 86.5 times higher than that of bulk BBO-COFBPY. The CuI/BBO-CROBPY+P27/SnO2/Pt photoelectrode with an area of 100 cm² displays an impressive ΔJ of 82.0 μA cm−2 with good durability. A flat photoelectrode surface and the generation of photogenerated charge carriers under light are observed using scanning electrochemical microscopy (SECM) as an in-situ technique. Density Functional Theory (DFT) calculation indicates that the asymmetry of the BBO unit prompts electrons to preferentially move in a defined direction upon light excitation in the small-molecular framework, thereby suppressing electron backflow. This work overcomes COF processability limitations in PEC water reduction and paves the way for using flexible devices.

Quasi-type-II Cu-In-Zn-S/Ni-MOF heterostructure with prolonged carrier lifetime for photocatalytic hydrogen production

Visible-driven photocatalytic hydrogen production using narrow-bandgap semiconductors has great potential for clean energy development. However, the widespread use of these semiconductors is limited due to problems such as severe charge recombination and slow surface reactions. Herein, a quasi-type-II heterostructure was constructed by combining bifunctional Ni-based metal–organic framework (Ni-MOF) nanosheets with BDC (1,4-benzenedicarboxylic acid) linker coupled with Cu-In-Zn-S quantum dots (CIZS QDs). This heterostructure exhibited a prolonged charge carrier lifetime and abundant active sites, leading to significantly improved hydrogen production rate. The optimized rate achieved by the CIZS/Ni-MOF heterostructure was 2642 μmol g−1 h−1, which is 5.28 times higher than that of the CIZS QDs. This improved performance can be attributed to the quasi-type-II band alignment between the CIZS QDs and Ni-MOF, which facilitates effective delocalization of the photogenerated electrons within the system. Additional photoelectrochemical tests confirmed the well-maintained photoluminescence and prolonged charge carrier lifetime of the CIZS/Ni-MOF heterostructure. This study provides valuable insights into the use of multifunctional MOFs in the development of highly efficient composite photocatalysts, extending beyond their role in light harvesting and charge separation.

Unveiling the Dual Role of Humidity: The Interplay with Defects Manipulating the Charge Carrier Lifetime in Metal Halide Perovskites.

Humidity has exhibited experimentally either beneficial or detrimental effects on the charge carrier lifetime of CH3NH3PbI3 perovskites, leaving the mechanism unresolved. By using ab initio nonadiabatic molecular dynamics simulations, we unveil the dual role of humidity stemming from the complex interplay between water and defects. Beneficially, water passivates iodine vacancies (VI) or grain boundaries (GBs), mitigating electron trapping by reducing nonadiabatic coupling and delaying charge recombination. However, when VI and GBs coexist, water molecules make the two unsaturated lead atoms approach closer and exacerbate electron trapping by deepening the Pb-dimer electron trap that was created by the VI defect, shortening the carrier lifetime to half of pristine CH3NH3PbI3. The study uncovers the origin of the positive and negative effects of humidity on the charge carrier lifetime of perovskites and offers strategies for improving perovskite devices, particularly by avoiding simultaneous point defects and GBs.

Transient‐Current Technique Characterization of Diamond Detector and Proposal of a Diamond Detector with Charge Amplification

Diamond holds promise as a potential candidate for future particle detectors owing to its remarkable electronic, mechanical, and thermal properties. However, a notable limitation is the need for a comprehensive model characterizing intrinsic diamond detectors. To address this, a specialized model integrated into the technology computer‐aided design simulation program is developed. The model's validation is accomplished through its application to the evaluation of an intrinsic diamond detector. Our investigation emphasizes three key attributes: charge carrier mobility, charge carrier lifetime, and the effective charge density within the bulk material. These attributes are carefully assessed using the transient current technique. Furthermore, our model serves as a valuable tool in the analysis of the quality of an high‐pressure high‐temperature diamond crystal and in the optimization of a diamond detector's design, exploiting the charge multiplication effect. This comprehensive methodology advances our grasp of diamond detector behavior and facilitates the development of even more sophisticated devices.