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Discovery of Novel Two-Dimensional Photovoltaic Materials Accelerated by Machine Learning
摘要： Searching for novel, high-performance, two-dimensional photovoltaic (2DPV) materials is an important pursuit for solar cell applications. In this work, an efficient method based on the machine learning algorithm combined with high-throughput screening is developed. Twenty-six 2DPV candidates are successfully ruled out from 187093 experimentally identified inorganic crystal structures, whose conversion efficiencies are predicted by density functional theory calculations. Our results indicate that Sb2Se2Te, Sb2Te3, and Bi2Se3 exhibit conversion efficiencies that are much higher than those of others, which make them promising 2DPV candidates for further applications. The superior photovoltaic performance is then analyzed, and the hidden structure-related relationships with photovoltaic properties are established, thus providing important information for the further examination of 2DPV materials. Given the rapid development of the database of materials, this approach not only provides an efficient way of searching for novel 2DPV materials but also can be applied to exploration of a broad range of functional materials.
关键词： high-throughput screening,machine learning,solar cell applications,density functional theory,two-dimensional photovoltaic materials
更新于2025-09-23 15:19:57
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Recent Progress in Indoor Organic Photovoltaics
摘要： Among various potential applications of organic photovoltaics (OPVs), indoor power generation has great potential because of several advantages over outdoor light harvesting under 1 sun condition. Commonly used indoor light sources have narrower emission spectra with lower intensity (by 3 orders of magnitude) as compared to the solar spectrum. Highly tunable optical absorption, large absorption coefficient, and small leakage currents under dim lighting conditions make OPVs promising candidates for indoor applications. For optimizing indoor photovoltaic materials and devices, several key issues (different from those under 1 sun condition), such as developing new indoor photovoltaic materials and devices with suitable absorption spectrum, large open-circuit voltage with low energy loss, minimized trap-mediated charge recombination and leakage currents, and device stability under indoor conditions, should be considered carefully. In this review, recent progresses in optimization of indoor photovoltaic materials and devices, and the key strategies to optimize the indoor photovoltaic characteristics will be summarized and discussed.
关键词： device optimization,light harvesting,organic photovoltaics,indoor power generation,photovoltaic materials
更新于2025-09-23 15:19:57
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Tailoring properties of hybrid perovskites by domain-width engineering with charged walls
摘要： Charged ferroelectric domain walls are fascinating electrical topological defects that can exhibit unusual properties. Here, in the search for novel phenomena, we perform and analyze first-principles calculations to investigate the effect of domain width on properties of domains with charged walls in the photovoltaic material consisting of methylammonium lead iodide hybrid perovskite. We report that such domains are stable and have rather low domain wall energy for any investigated width (that is, up to 13 lattice constants). Increasing the domain width first linearly decreases the electronic band gap from ?1.4 eV to about zero (which therefore provides an efficient band-gap engineering), before the system undergoes an insulator-to-metal transition and then remains metallic (with both the tail-to-tail and head-to-head domain walls being conductive) for the largest widths. All these results can be understood in terms of: (i) components of polarization along the normal of the domain walls being small in magnitude; (ii) an internal electric field that is basically independent of the domain width; and (iii) rather negligible charge transfer between walls. These findings deepen the knowledge of charged ferroelectric domain walls and can further broaden their potential for applications, particularly in the context of halide perovskites for photovoltaics.
关键词： charged ferroelectric domain walls,hybrid perovskites,photovoltaic materials,band-gap engineering,insulator-to-metal transition
更新于2025-09-23 15:19:57
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Understanding the Defect Properties of Quasi-2D Halide Perovskites for Photovoltaic Applications
摘要： Quasi-2D halide perovskites have emerged as one of the most promising photovoltaic materials owing to their excellent stability, yet the device power conversion efficiency (PCE) is far from satisfactory. Beside of crystal orientation related carrier transport, defects in absorbers also play a crucial role in device performance, which receives limited attention in the 2D perovskite field. Herein we systematically profiled the defects states in 2D perovskite film by the temperature-dependent admittance spectroscopy (AS), light-intensity-dependent VOC, space-charge-limited-circuit (SCLC), and photoluminescence measurements. It is revealed that the Quasi-2D perovskite films suffer from severe defects as compared to the 3D counterparts in terms of both trap energy levels and trap densities. Consequently, nonradiative recombination of photogenerated carriers is much greater in the corresponding devices, wherein the monomolecular recombination is dominant. These findings substantially benefit a deeper understanding of the nature of 2D perovskite materials, which promotes the further design of 2D perovskite solar cells.
关键词： carrier recombination,Quasi-2D halide perovskites,defects properties,photovoltaic materials,solar cells
更新于2025-09-19 17:13:59
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Formation Thermodynamics, Stability, and Decomposition Pathways of CsPbX <sub/>3</sub> (X = Cl, Br, I) Photovoltaic Materials
摘要： Standard enthalpies of formation of CsPbX3 (X = Cl, Br, I) perovskites from halides and from elements at 298 K were measured using solution calorimetry. Intrinsic and extrinsic stabilities of CsPbX3 halides were analyzed and compared with those of CH3NH3PbX3. The main difference between the stabilities of CsPbX3 and CH3NH3PbX3 halides was found to stem from the different chemical nature of cesium and methylammonium cations. Indeed, the enthalpies of formation of CsPbX3 from binary constituent halides, ?fH○hal, are only slightly more negative than those of CH3NH3PbX3. Small values of ?fH○hal imply that the entropic contribution to the Gibbs free energy of formation of CsPbX3 and CH3NH3PbX3 is significant and, hence, of utmost importance for understanding the intrinsic stability of these compounds and their analogs. Regarding the extrinsic stability, the presence of gaseous O2, H2O, and CO2 was shown to be crucial for the stability of the iodide, CsPbI3, for which several decomposition reactions, exergonic at 298 K, were identified. At the same time, chloride, CsPbCl3, and bromide, CsPbBr3, are much less sensitive to these chemical agents. However, liquid water should degrade all the CsPbX3 halides.
关键词： Plasmonics,Stability,Decomposition Pathways,Hybrid Materials,Thermodynamics,Magnetic,Photovoltaic Materials,CsPbX3,Optical
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE PES/IAS PowerAfrica - Abuja, Nigeria (2019.8.20-2019.8.23)] 2019 IEEE PES/IAS PowerAfrica - Recent advances in solar energy harvesting materials with particular emphasis on photovoltaic materials
摘要： The use of solar energy, as an alternative to the conventional fossil fuel based resources, has increased tremendously over the years due to its enormous and environmentally benign nature. In an effort to make solar energy harnessing more efficient and affordable, various technologies have been developed. The solar thermal technologies have achieved very impressive solar conversion efficiencies and are fully commercialized. However, PV technology is still undergoing rapid evolution in an effort to achieve high efficiencies and to reduce the cost. New materials, concepts and approaches in solar cell development have become the center of research in this field. This article gives a review on the progress of PV technology with a keen interest on the emerging PV materials that hold the prospects for achieving high efficiencies at low costs.
关键词： Photovoltaic materials,thin films,perovskite solar cells,third generation solar cells,Efficiency
更新于2025-09-16 10:30:52
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Rationally designed CuSb1-Bi S2 as a promising photovoltaic material: Theoretical and experimental study
摘要： Here we report the miscibility gap of CuSb 1- x Bi x S 2 (CABS), a promising photo energy conversion material for band gap engineered solar cells, and evaluate its applicability via a combination of theoretical predictions and experimental verifications. Our ab initio calculations and thermodynamic modeling revealed that the CABS random alloy system has optimal band gap values in the range of 1.1–1.5 eV when synthesized at room temperature. The CABS system, synthesized by mechanochemical methods, exhibited optical band gap values in very good agreement with theoretical predictions, as well as lowered kinetic energy barriers for enhanced nucleation.
关键词： Photovoltaic materials,Chalcogenide,Mechanochemical method,Solar cells,I–V–VI
更新于2025-09-16 10:30:52
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Structural Origins of Light-Induced Phase Segregation in Organic-Inorganic Halide Perovskite Photovoltaic Materials
摘要： Light-induced phase segregation in mixed-halide perovskite photovoltaic materials results in the formation of low-band-gap regions that limit the voltage of devices. This work explores the dependence of this light instability on crystal structure and maps it across the cubic-tetragonal solvus in the (CsyFA1?y)Pb(BrxI1?x)3 phase diagram.
关键词： organic-inorganic halide perovskite,cubic-tetragonal solvus,photovoltaic materials,light-induced phase segregation,crystal structure
更新于2025-09-12 10:27:22
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New Optimal Control Problems in Density Functional Theory Motivated by Photovoltaics
摘要： We present and study novel optimal control problems motivated by the search for photovoltaic materials with high power-conversion e?ciency. The material must perform the ?rst step: convert light (photons) into electronic excitations. We formulate various desirable properties of the excitations as mathematical control goals at the Kohn–Sham-DFT level of theory, with the control being given by the nuclear charge distribution. We prove that nuclear distributions exist which give rise to optimal HOMO-LUMO excitations, and we present illustrative numerical simulations for one-dimensional ?nite nanocrystals. We observe pronounced goal-dependent features such as large electron-hole separation and a hierarchy of length scales: internal HOMO and LUMO wavelengths < atomic spacings < (irregular) ?uctuations of the doping pro?les < system size.
关键词： optimal control,excitations,photovoltaic materials,density functional theory,Kohn–Sham equations
更新于2025-09-12 10:27:22
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First-Principles Screening of Lead-Free Mixed-Anion Perovskites for Photovoltaics
摘要： Organic-inorganic hybrid lead perovskites have made rapid progress in photovoltaic fields. However, the toxicity and poor long-term stability of these materials still limit their further commercial application. Herein, we proposed a system of lead-free mixed-anion perovskites in which a chalcogen element is incorporated into the perovskite octahedrons to improve the system stability. We performed first-principles calculations of the bandgaps of 192 lead-free mixed-anion perovskites belonging to the class of ABX'X"2, where A=Cs+, CH3NH3+, and HC(NH2)2+; B=Ga3+, In3+, Sb3+, Bi3+; X'= O2-, S2-, Se2-, and Te2-, and X"= F-, Cl-, Br-, and I-. The bandgap shows a linear relationship with the average anion electronegativity. The contribution of anions to the band edge states is related to electron affinity and structure parameters. Considering multiple factors forming perovskites, we screened out a promising candidate, CsInOBr2, with a suitable bandgap (1.3 eV) for application in photovoltaics.
关键词： theoretical screening,GLLB-SC methods,photovoltaic materials,lead-free perovskites,bandgap
更新于2025-09-12 10:27:22