Photovoltaic Applications Research Articles

Origin of Persisting Photoresponse of One-Year Aged Two-Dimensional Lead Halide Perovskites Stored in Air under Dark Conditions.

Two-dimensional halide perovskites are promising for advanced photonic, optoelectronic, and photovoltaic applications. However, their long-term stability is still a critical factor limiting their implementation into further commercial applications. Here, we present an environmental stability analysis of BA2(MA)n-1PbnI3n+1 (BA = C4H12N+, MA = CH6N+) two-dimensional perovskites with the lowest quantum well thicknesses of n = 1 and n = 2, after 1 year of aging under ambient humidity, oxygen content, and light conditions. We observed that both crystal phases (n = 1 and 2) degraded similarly, resulting in the removal of organic components and crystal decomposition into PbI2, Pb oxides, and Pb hydroxides. However, we have found a significant difference between their aging under ambient light and dark conditions, affecting their degraded morphology and photoactivity. Both crystal phases exposed to ambient light aged into a morphology characterized by the formation of several pinholes and voids, accompanied by photoluminescence degradation. Samples stored under dark conditions surprisingly preserved their photoluminescence activity, which morphologically aged into microrod structures. We conclude that the observed loss of photoactivity of 2D perovskites aged under ambient light is attributed to photoaccelerated degradation processes causing faster crystal surface photo-oxidation accompanied by a creation of multiple I vacancies and hydration of the inner crystal. The retainment of photoactivity in 2D perovskites aged under dark conditions is attributed to slower surface oxidation processes into Pb salts, as confirmed by X-ray photoemission spectroscopy. The formed surface layer even allows for a layer-by-layer degradation and acts as a protection barrier against further additional loss of I atoms and the consequent hydration of the inner part of samples. We demonstrate that light is the most critical external factor accelerating 2D perovskite degradation processes in ambient air and thus affecting their long-term stability. We conclude in this work that perovskite material structural engineering together with their surface passivation or encapsulation strategical techniques applied is an essential step for their further application into long-term stable commercial devices.

CsPbBr3-PbSe Perovskite-Chalcogenide Epitaxial Nanocrystal Heterostructures and Their Charge Carrier Dynamics.

Lead halide perovskite and chalcogenide heterostructures which share the ionic and covalent interface bonding may be the possible materials in bringing phase stability to these emerging perovskite nanocrystals. However, in spite of significant successes in the development of halide perovskite nanocrystals, their epitaxial heterostructures with appropriate chalcogenide nanomaterials have largely remained unexplored. Keeping the importance of these materials in mind, herein, epitaxial nanocrystal heterostructures of CsPbBr3-PbSe are reported. The shape remained rhombic dodecahedral-tetrahedral, and the phase retained orthorhombic-cubic for CsPbBr3 and PbSe nanocrystals, respectively. These are synthesized following the standard classical approach of heteronucleations of chalcogenide PbSe with CsPbBr3 perovskite nanostructures and characterized with high-resolution electron microscopic imaging. With an ultrafast study, the hot charge transfer from CsPbBr3 to PbSe is also established. As these are first of its kind nanostructures which are obtained with heteronucleation and growth of chalcogenides on halide perovskites, this finding is expected to open the roadmap for designing other heterostructures which are important for catalysis and photovoltaic applications.

Computational modeling of Cs3Sb2I9-based novel architecture under WLED illumination for indoor photovoltaic applications

Computational modeling of Cs3Sb2I9-based novel architecture under WLED illumination for indoor photovoltaic applications

Optimization of the solar cell based on cadmium telluride by adding the CdSeTe absorbing layer (heterostructure simulation)

Cadmium telluride solar cells are among the most common devices for photovoltaic applications. However, the energy conversion efficiency of these elements remains insufficiently high. Using the SCAPS programming environment, research and optimization of a classical thin-film solar cell based on CdTe were carried out. The structure of this element consisted of ITO as a transparent conductive contact, a cadmium sulfide (CdS) layer, and a cadmium telluride (CdTe) absorber layer with a metal contact. To optimize this structure in terms of power conversion efficiency, the influence of the thickness and concentration of acceptor impurities in the CdTe absorbing layer, as well as the influence of the thickness and concentration of donor impurities in the CdS buffer layer, were considered. It was established that the optimal thicknesses for the CdS buffer layer and absorption CdTe layers are 50 nm and 3000 nm, respectively. An additional CdSeTe layer between the CdS and CdTe layers has been proposed as one of the optimization options to improve the device efficiency. The main photovoltaic parameters of such a solar cell were analyzed depending on the thickness of the CdSeTe layer and its selenium content. It has been demonstrated that adding CdSeTe solid solution to the 1500 nm thick CdTe absorber layer increases the efficiency of the solar cell by 6.84 %. The main photovoltaic characteristics of CdS/CdTe and CdS/CdSeTe/CdTe solar cells were compared. The results showed that the simulated CdS/CdSeTe/CdTe structure provides better photoconversion efficiency in the AM1.5G light spectrum compared to the classical CdS/CdTe structure. Such elements can be used to form highly efficient solar panels

Computational Investigation on Ultrawideband MXene-Based Metamaterial Absorber for the Photonics and Photovoltaic Applications

Computational Investigation on Ultrawideband MXene-Based Metamaterial Absorber for the Photonics and Photovoltaic Applications

Dynamics of Photoinduced Charge Carriers in Metal-Halide Perovskites

The measurement and description of the charge-carrier lifetime (τc) is crucial for the wide-ranging applications of lead-halide perovskites. We present time-resolved microwave-detected photoconductivity decay (TRMCD) measurements and a detailed analysis of the possible recombination mechanisms including trap-assisted, radiative, and Auger recombination. We prove that performing injection-dependent measurement is crucial in identifying the recombination mechanism. We present temperature and injection level dependent measurements in CsPbBr3, which is the most common inorganic lead-halide perovskite. In this material, we observe the dominance of charge-carrier trapping, which results in ultra-long charge-carrier lifetimes. Although charge trapping can limit the effectiveness of materials in photovoltaic applications, it also offers significant advantages for various alternative uses, including delayed and persistent photodetection, charge-trap memory, afterglow light-emitting diodes, quantum information storage, and photocatalytic activity.

Probing Nanoscale Charge Transport Mechanisms in Quasi-2D Halide Perovskites for Photovoltaic Applications.

Quasi-2D layered halide perovskites (quasi-2DLPs) have emerged as promising materials for photovoltaic (PV) applications owing to their advantageous bandgap for absorbing visible light and the improved stability they enable. Their charge transport mechanism is heavily influenced by the grain orientation of their crystals as well as their nanostructures, such as grain boundaries (GBs) and edge states─the formation of which is inevitable in polycrystalline quasi-2DLP thin films. Despite their importance, the impact of these features on charge transport remains unexplored. In this study, we conduct a detailed investigation on polycrystalline quasi-2DLP thin films and devices, carefully analyzing how grain orientation and nanostructures influence charge transport. Employing nondestructive atomic force microscopy (AFM) topography, along with transient absorption spectroscopy (TAS) and grazing-incidence wide-angle X-ray scattering (GIWAXS), we obtained significant insights regarding the phase purity, crystallographic information, and morphologies of these films. Moreover, our systematic investigation using AFM-based techniques, including Kelvin probe force microscopy (KPFM) and conductive AFM (c-AFM), elucidates the roles played by GBs and edge states in shaping charge transport behavior. In particular, the local band structure along the GBs and edge states within both vertical and parallel grains was found to selectively repel electrons and holes, thus facilitating charge carrier separation. These findings provide perspectives for the development of high-performance quasi-2DLP PV devices and highlight potential approaches that can leverage the intrinsic properties of quasi-2DLPs to advance the performance of perovskite solar cells.

Impact of Metal Deposition on the Optical and Interface Properties of NiO: Growth and Characterization of NiO/Metal Thin Bilayer Films

Abstract Since transparent conductive oxides (TCOs) provide electrical conductivity together with optical transparency, they have found wide applications in optoelectronic devices and photovoltaics. Among the TCOs, nickel oxide (NiO) is challenging due to its inherent trade-off between transparency and electrical conductivity. To address this challenge, one effective approach is to deposit a metal layer onto NiO thin films. In this work, NiO, NiO/Au, NiO/Ag, and NiO/Cu thin films are prepared by sputtering and thermal evaporation technique on glass substrates and fully characterized finding the proper film for optoelectronic applications. The electrical and optical properties of the fabricated films are examined by four-point probe measurements and optical spectrometry. According to the obtained results, the NiO/Au, NiO/Ag, and NiO/Cu bilayers show sheet resistance of 200, 338, and 925 Ω / sq respectively while their optical bandgaps vary from 3.2 to 3.76 eV. These findings provide valuable insights into the perfor-mance of these films, making them potentially viable choices for various optoelectronic applications.

Generation of Database of Polymer Acceptors and Machine Learning‐Assisted Screening of Efficient Candidates

ABSTRACTThis paper presents a comprehensive approach for designing polymer acceptors for organic photovoltaic applications through the generation of an extensive database and the application of machine learning (ML) techniques. Over 40 ML models are trained for the prediction of power conversion efficiency (PCE). Histgradient boosting regressor has appeared as best model. Almost 10 k polymers are generated and their PCE values are predicted. The chemical space of polymers has been visualized and analyzed. Cluster analysis revealed significant differences among the selected polymers. Additionally, an assessment of synthetic accessibility for these polymers indicated that the majority can be synthesized with relative ease.

Heterogeneous Nucleation Regulation Amends Unfavorable Crystallization Orientation and Defect Features of Antimony Selenosulfide Film for High‐Efficient Planar Solar Cells

AbstractAntimony selenosulfide (Sb2(S,Se)3) has obtained widespread concern for photovoltaic applications as a light absorber due to superior photoelectric features. Accordingly, various deposition technologies have been developed in recent years, especially hydrothermal deposition method, which has achieved a great success. However, device performances are limited with severe carrier recombination, relating to the quality of absorber and interfaces. Herein, bulk and interface defects are simultaneously suppressed by regulating heterogeneous nucleation kinetics with barium dibromide (BaBr2) introduction. In details, the Br adsorbs and dopes on the polar planes of cadmium sulfide (CdS) buffer layer, promoting the exposure of nonpolar planes of CdS, which facilitates the favorable growth of [hk1]‐Sb2(S,Se)3 films possessing superior crystallinity and small interface defects. Additionally, the Se/S ratio is increased due to the replacement of Se by Br, causing a downshift of the Fermi levels with a benign band alignment and a shallow‐level defect. Moreover, Ba2+ is located at grain boundaries by coordination with S and Se ions, passivating grain boundary defects. Consequently, the efficiency is increased from 7.70 % to 10.12 %. This work opens an avenue towards regulating the heterogeneous nucleation kinetics of Sb2(S,Se)3 film deposited via hydrothermal deposition approach to optimize its crystalline orientation and defect features.

Design and performance exploration of Pb-free low-cost all-inorganic perovskite-inspired CuAgBi2I8 solar cells: theoretical approach

Abstract Organic–inorganic halide perovskites have demonstrated great potential for photovoltaic applications owing to their unprecedented optoelectronic properties and low manufacturing costs. However, the commercialization of this technology is hindered by its thermal instability and inherent toxicity. In this study, SCAPS-1D simulation software was used to study the performance of solar cell based on CuAgBi2I8, which is a novel inorganic non-toxic lead-free perovskite-inspired material. Different electron transport layers (TiO2, In2S3, ZnO, Zn0.75Mg0.25O,SnO2 and SrTiO3) and hole transport layers (CuI, PEDOT:PSS, CuSCN and Cu2O) were studied, our research indicated that SnO2 and NiO formed the optimal combination. Further analysis revealed that the optimal absorption layer thickness was 900 nm, the absorption layer doping concentration should be less than 1 × 1013 cm−3 and the defect density should be less than 1 × 1014 cm−3. The optimal thickness of SnO2 and NiO was 30 nm, the optimal doping concentration of SnO2 and NiO was 1 × 1020 cm−3, the defect density of absorber layer/SnO2 and absorber layer/NiO interfaces should be less than 1 × 1012 cm−3, C was the optimal back electrode material. Consequently, the optimal device configuration was identified as FTO/SnO2/CuAgBi2I8/NiO/C, the efficiency was improved from original 2.76% to 19.10% after above optimization. These results indicate that solar cell with CuAgBi2I8 as the absorber layer is a potential alternative to organic–inorganic lead halide perovskite solar cells.

Leveraging Phenazine‐Based Ligands for Optimized Perovskite Optoelectronic Performance Through Chelation and Redox Engineering

AbstractPerovskite nanocrystals (PNCs) hold immense potential for optoelectronic and photovoltaic applications. However, their performance is hindered by surface defects that promote non‐radiative recombination and reduce stability. Surface engineering, particularly through defect passivation, is crucial for achieving high‐performing perovskite solar cells. Chelation has been shown to significantly improve the efficiency and stability of perovskite solar cells. In this study, a novel chelation strategy using 1,10‐Phenanthroline (Phen) is presented as a bidentate chelating ligand to effectively target and passivate these detrimental surface defects. By strategically designing a Phenanthroline derivative, dipyrido[3,2‐a:2′,3′‐c]phenazin‐11‐amine (Phen‐derivative) with optimized redox potentials, dual functionality: efficient defect passivation and hole transport is achieved. X‐ray photoelectron spectroscopy (XPS) confirms the superior binding capability of the Phen‐derivative due to chelation. This strong interaction facilitates efficient and ultrafast charge transfer from PNCs and the formation of a long‐lived charge‐separated state, as evidenced by sustained bleaching in transient absorption spectra. A metal‐dipyrido[3,2‐a:2′,3′‐c]phenazin‐11‐amine complex (Ir‐complex) derived from dipyrido[3,2‐a:2′,3′‐c]phenazin‐11‐amine, but lacking a chelation site, hinders desired hole transfer despite similar charge transfer energetics. This work emphasizes the critical role of chelation‐mediated interfacial interactions and energy alignment in designing effective charge shuttle molecules and unlocking the potential of lead‐chelating hole transporters for next‐generation light‐harvesting technologies.

Enhanced UV Light Responsivity in <110>‐Oriented 2D Perovskites Realized by Pressure‐induced Ultrafast Exciton Transport

Two‐dimensional (2D) <100>‐oriented perovskites exhibit superior optoelectronic properties, offering significant potential in photovoltaic, light‐emitting, and photodetection applications. Nevertheless, their enlarged interlayer spacing restricts longitudinal carrier transport, thereby limiting its potential applications. While <110>‐oriented 2D perovskites provide a prospective solution with their compact interlayer spacing, their inherent structure, characterized by octahedra tilting, indirectly hinders carrier transport due to the generation of self‐trapped excitons (STEs) caused by strong electron‐phonon coupling. Here, we adeptly regulate the photoluminescence (PL) from STEs to free excitons (FEs) emission within the 2D <110>‐oriented (API)PbBr4 single crystal through structure optimization under pressure treatment. Besides, we observed anisotropic FE transport with an anisotropy ratio of 4.97. The exciton mobility reaches a peak of 93.6 cm2 V‐1s‐1 at 2.7 GPa, a value comparable to those of their three‐dimensional (3D) counterparts, which is attributed to a reduction in electron‐phonon coupling and exciton reduced mass. Additionally, this ultrafast exciton transport significantly enhances UV light responsivity, exhibiting an increase of approximately 5000 times at 2.7 GPa in comparison to ambient conditions. These findings highlight the prospective application of 2D <110>‐oriented perovskites in high‐performance optoelectronic devices through intrinsic structural modulation.

Enhanced UV Light Responsivity in -Oriented 2D Perovskites Realized by Pressure-induced Ultrafast Exciton Transport.

Two-dimensional (2D) <100>-oriented perovskites exhibit superior optoelectronic properties, offering significant potential in photovoltaic, light-emitting, and photodetection applications. Nevertheless, their enlarged interlayer spacing restricts longitudinal carrier transport, thereby limiting its potential applications. While <110>-oriented 2D perovskites provide a prospective solution with their compact interlayer spacing, their inherent structure, characterized by octahedra tilting, indirectly hinders carrier transport due to the generation of self-trapped excitons (STEs) caused by strong electron-phonon coupling. Here, we adeptly regulate the photoluminescence (PL) from STEs to free excitons (FEs) emission within the 2D <110>-oriented (API)PbBr4 single crystal through structure optimization under pressure treatment. Besides, we observed anisotropic FE transport with an anisotropy ratio of 4.97. The exciton mobility reaches a peak of 93.6 cm2V-1s-1 at 2.7 GPa, a value comparable to those of their three-dimensional (3D) counterparts, which is attributed to a reduction in electron-phonon coupling and exciton reduced mass. Additionally, this ultrafast exciton transport significantly enhances UV light responsivity, exhibiting an increase of approximately 5000 times at 2.7 GPa in comparison to ambient conditions. These findings highlight the prospective application of 2D <110>-oriented perovskites in high-performance optoelectronic devices through intrinsic structural modulation.

Suppressing Static and Dynamic Disorder for High-Efficiency and Stable Thick-Film Organic Solar Cells via Synergistic Dilution Strategy.

Developing stable and highly efficient thick-film organic solar cells (OSCs) is crucial for the large-scale commercial application of organic photovoltaics. A novel synergistic dilution strategy to address this issue, using Polymethyl Methacrylate (PMMA) -modified zinc oxide (ZnO) as the interfacial layer, is introduced. This strategy effectively mitigates oxygen defects in ZnO while also regulating the self-assembly process of the active layer to achieve an ordered distribution of donors and acceptors. In synergistic diluted devices, the dynamic disorder is reduced owing to the suppression of electron-phonon coupling, while the static disorder is suppressed by improved molecular stacking and enhanced intermolecular interactions. Consequently, the 300nm PM6:L8-BO device post-synergistic dilution manifests a marked enhancement in device performance, achieving a photovoltaic power conversion efficiency (PCE) >17% with excellent thermal stability. A typical ternary system is selected to explore the general applicability of synergistic dilution strategy, the PCE has been enhanced significantly from 17.89% to 18.72%, which falls within the range of the highest values among inverted single junction OSCs. As a practical application that depends on the pivotal synergy between high efficiency and stability, this approach paves the way for large-scale implementation of OSCs and ensures cost-effectiveness.

Semitransparent Cu2O films based on CuO Back Layer for Photoelelctrochemical Water Splitting and Photovoltaic Applications.

Cuprous oxide (Cu2O) as an intrinsic p-type semiconductor is promising for solar energy conversion. The major challenge in fabricating Cu2O lies in achieving both high transparency and high performance in a tandem device. The Cu2O photocathodes often employ gold as the back contact layer. However, it is not an optimal choice in tandem device due to its poor transmission, scarcity, and electron-hole recombination at the interface of Au and Cu2O. Here, we presented a facile method that utilizes the earth-abundant material copper oxide (CuO) to fabricate highly transparent Cu2O devices. The maximum transmittance of the Cu2O film on CuO (FTO/CuO/Cu2O) increased from 42% to 58% compared with Cu2O film on Au (FTO/Au/Cu2O) in 550-800 nm. After coating atomic layer deposition (ALD) layers and hydrogen evolution reaction (HER) catalyst, the photocurrent density at 0 V (versus RHE) of the semitransparent Cu2O photocathode with CuO as the back layer for photoelectrochemical (PEC) water splitting reached -4.9 mA·cm-2, which showed a 24.5% improvement compared with FTO/Au/Cu2O photocathode. Moreover, expanding the CuO layer strategy to the field of solar cells enables Cu2O solar cells to achieve a PCE of 2.37%.

A Holistic Multi-Criteria Assessment of Solar Energy Utilization on Urban Surfaces

Urban surfaces such as rooftops, facades, and infrastructure offer significant potential for solar energy integration, contributing to energy efficiency and sustainability in cities. This article introduces an advanced multi-criteria assessment (MCA) framework designed to evaluate the suitability of various urban surfaces for solar energy deployment. The framework extends beyond traditional economic, environmental, and technological factors to include social, political, legal, health and safety, cultural, and psychological dimensions, providing a comprehensive evaluation of photovoltaic (PV) applications in urban contexts. By synthesizing existing literature and applying this holistic MCA framework, this research offers valuable insights for urban planners, architects, and policymakers, enabling strategic optimization of solar energy integration in urban environments. The findings underscore the importance of sustainable urban development and climate resilience, highlighting key factors influencing solar technology deployment and proposing actionable recommendations to address existing challenges.

Transformerless High Voltage Gain Y-Source DC–DC Converter with Switched Capacitor for Grid-Connected Photovoltaic Applications

A high voltage gain DC–DC converter with a Y-source network is proposed in this paper for applications such as fuel cells and PV systems. The proposed converter topology is a combination of a Y-source module with a switched capacitor boost module. It is a single switch topology to produce high voltage gain at the load. The superiority of the proposed topology is the high voltage transfer ratio and continuous input current. The voltage gain of the converter can be achieved up to twenty times the input voltage at a duty cycle of 25% itself. The steady state analysis of the converter is carried out using mathematical equations and the working of the converter is explained. The design and analysis of the passive components in the circuit are explained. To illustrate the highlights of the converter, the proposed topology is compared with similar converters in the literature. The simulation of the converter is carried out using MATLAB/SIMULINK. The circuit is verified in the laboratory using a 100[Formula: see text]W prototype.

Improved Charge‐Transfer Doping in Crystalline Polymer for Efficient and Stable Perovskite Solar Cells

AbstractPerovskite solar cells (PSCs) have significant potential for next‐generation photovoltaic technology applications. However, the instability of hole transport layers (HTLs) becomes the major obstacle to long‐term operational devices, which are affected by the intrinsic thermal instability and loose structure of hole transport materials, as well as the hygroscopicity and migration of dopants. Here, poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) is used as a model crystalline polymer to thoroughly investigate effective p‐type doping strategies and the underlying mechanism. According to Hard–Soft‐Acid–Base theory, the soft base P3HT is more likely to form a stable Lewis acid–base adduct with the reactive soft acid radical, resulting in a strong charge‐transfer interaction, thereby enhancing conductivity and regulating the energy band of the HTL. Meanwhile, the radical cation salt can promote pre‐nucleation to optimize the crystallization orientation of P3HT. The resulting PSCs exhibited the efficiency of 25.16%, which is the highest efficiency reported so far based on doped P3HT. In addition, the resulting devices demonstrated excellent stability, maintaining 96.5%, 96%, and 91% of their initial efficiency after aging under continuous illumination for 2028 h, at 85 °C for 1080 h, and at maximum power point (MPP) tracking under continuous 1 Sun illumination at 85 °C for 528 h, respectively.

High temperature dependent absorber-emitter pair nanostructure metamaterial matched with low band-gap PV cell for solar thermo photovoltaic application

High temperature dependent absorber-emitter pair nanostructure metamaterial matched with low band-gap PV cell for solar thermo photovoltaic application