Search Results (209)

The tin dioxide (SnO₂) thin films in this work were prepared by using plasma-enhanced atomic layer deposition (PEALD), and a systematic analysis was conducted to evaluate the influence of post-deposition annealing at various temperatures in a nitrogen–hydrogen mixed atmosphere on their surface morphology, optical behavior, and electrical performance. The SnO₂ films were characterized by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Hall effect measurements. With increasing annealing temperatures, the SnO₂ films exhibited enhanced crystallinity, a higher oxygen vacancy (O_V) peak area ratio, and improved mobility and carrier concentration. These enhancements make the annealed SnO₂ films highly suitable as electron transport layers (ETLs) in perovskite solar cells (PSCs), providing practical guidance for the design of high-performance PSCs. Full article

Three-dimensional/two-dimensional bilayered perovskite solar cells have recently become popular for ensuring high efficiency and promising long-term stability. The 3D/2D bilayered perovskite thin film is mainly used in regular (n-i-p)-type perovskite solar cells. In this review, our discussion also focuses on the regular kind of perovskite solar cells. In a 3D/2D bilayered perovskite thin film, the 2D perovskite layer works as a capping layer on top of the 3D perovskite thin film. The 2D capping layer heals the surface and bulk defects of the 3D perovskite thin film. The 2D layer interfaces between the 3D perovskite and hole transport layers. The 2D layer also acts as a shield against moisture and heat. This layer also inhibits ion migration between layers (3D perovskite and back contact). This review lists and investigates different organic precursors deposited as a 2D capping layer on top of the 3D perovskite thin film to explore their impact on the solar cell’s efficiency and stability. The possible challenges and remedies in growing a 2D capping layer on top of the 3D perovskite thin film are also discussed. Full article

Perovskite, as a promising candidate for the next generation of photovoltaic materials, has attracted extensive attention. To date, the power conversion efficiency (PCE) of perovskite solar cells (PSCs) has reached 26.7%, which is competitive with that of commercial silicon cells. However, high PCE is usually achieved in devices with a small surface area fabricated by the spin-coating method. Perovskite thin films, as the most important layer, suffer from poor uniformity and crystallization caused by the large-area fabrication process, which leads to a dramatic drop in efficiency and exhibits poor reproducibility. Here, we summarize common architectures of PSC and perovskite solar modules (PSMs), as well as analyzing the reasons for efficiency loss on the modules. Subsequently, the review describes the mechanism of perovskite growth in detail, and then sums up recent research on small-to-large-area perovskite devices. Large-area fabrication methods mainly include blade coating, slot-die coating, spray-coating, inkjet printing, and screen printing. Moreover, we compare the advantages and disadvantages of each method and their corresponding mechanisms and research progress. The review aims to provide potential logical conclusions and directions for the commercial large-area perovskite fabrication process. Full article

Perovskite solar cells have garnered significant attention due to their outstanding optoelectronic properties, ease of fabrication, and cost-effectiveness, making them a promising candidate for next-generation photovoltaic technologies. However, CsPbIBr₂-based perovskites currently face critical challenges regarding their limited efficiency and relatively poor long-term stability, hindering their broader commercial applications. In this study, we systematically investigated the morphological effects induced by different solvents, including dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), and dimethyl sulfoxide (DMSO), on the formation and characteristics of lead bromide (PbBr₂) complexes. Further optimization was achieved through the innovative incorporation of trimesoyl chloride (TMC) doping into the perovskite precursor solution. The optimized precursor solution was subsequently processed using a spin-coating and annealing method, resulting in high-quality CsPbIBr₂ perovskite thin films with improved morphological and optoelectronic properties. The experimental results demonstrated a remarkable enhancement in power conversion efficiency (PCE), with an increase from an initial value of 6.2% up to 10.2%. Furthermore, the optimized CsPbIBr₂ solar cells exhibited excellent stability, maintaining over 80% of their initial efficiency after continuous aging for 250 h in ambient air conditions. This study presents an effective strategy for the controlled morphological and compositional engineering of wide-bandgap perovskite materials, providing a significant step forward in the advancement of perovskite photovoltaic technology. Full article

Azulene has been attracting much attention as a charge transfer material in organic electronics due to its inherent large dipole moment and small band gap, but its application in perovskite solar cells (PSCs) is very limited. Herein, azulene was applied as the core acceptor for hole transport materials (HTMs), and two molecules named Azu-Py-DF and Azu-Py-OMeTPA were designed and synthesized, in which 4-pyridyl was introduced on the 6-position of the 1,3-substituted azulene core to adjust energy levels. The different spatial orientations of pyridine and the azulene core improve the solubility and reduce the crystallinity of the material, which is conducive to creating a thin film morphology. Azu-Py-OMeTPA exhibited good hole and electron mobility compared with standard Spiro-OMeTAD. Applied as an HTM in PSCs, the Azu-Py-OMeTPA-based device achieved a power conversion efficiency (PCE) of 18.10%, which is higher than that of the 6-position unsubstituted counterpart. Nevertheless, the anticipated passivation effect of the 4-pyridyl group was diminished due to the electron-deficient nature of azulene’s seven-membered ring. These results demonstrate that optimizing the structure of azulene-based HTMs can significantly alter molecular spatial structure, film formation properties, electron delocalization characteristics and charge transport, and can lead to improved device performance, providing insights for the future design of novel HTMs. Full article

Flexibility, light weight, and mechanical robustness are the key advantages of flexible photovoltaic (PV) modules, making them highly versatile for sustainable energy solutions. Unlike traditional rigid PV modules, their flexible nature makes them incredibly versatile for harnessing energy in places where doing so was once impossible. They have a wide range of applications due to their flexibility and moldability, making it possible to conform these modules to surfaces like curved rooftops and other irregular structures. In this paper, we provide a comprehensive review of all the materials used in flexible PV modules with a focus on their role in sustainability. We thoroughly discuss the active-layer materials for crystalline silicon (c-Si)-based solar cells (SC) and thin-film solar cells such as cadmium telluride (CdTe), as well as copper indium gallium diselenide (CIGS), amorphous thin-film silicon (a-Si), perovskite and organic solar cells. Various properties, such as the optical, barrier, thermal, and mechanical properties of different substrate materials, are reviewed. Transport layers and conductive electrode materials are discussed with a focus on emerging trends and contributions to sustainable PV technology. Various fabrication techniques involved in making flexible PV modules, along with advantages, disadvantages, and future trends, are highlighted in the paper. The commercialization of flexible PV is also discussed, which is a crucial milestone in advancing and adapting new technologies in the PV industry with a focus on contributing toward sustainability. Full article

We present structural, morphological, optical and photocatalytic properties of multiferroic Bi_0.98Ba_0.02FeO₃ (BBFO2) perovskite thin films prepared by a combined sol–gel and spin-coating method. X-ray diffraction (XRD) analysis revealed that all the perovskite films consisted of the stable polycrystalline rhombohedral phase structure (space group R3c) with a tolerance factor of 0.892. By using Rietveld refinement of diffractogram XRD data, crystallographic parameters, such as bond angle, bond length, atom position, unit cell parameters, and electron density measurements were computed. Scanning electron microscopy (SEM) allowed us to assess the homogeneous and smooth surface morphology of the films with a small degree of porosity, while chemical surface composition characterization by X-ray photoelectron spectroscopy (XPS) showed the presence of Bi, Fe, O and the doping element Ba. Absorption measurements allowed us to determine the energy band gap of the films, while photoluminescence measurements have shown the presence of oxygen vacancies, which are responsible for the enhanced photocatalytic activity of the material. Photocatalytic degradation experiments of Methylene Blue (MB), Methyl orange (MO), orange G (OG), Violet and Rhodamine B (RhB) performed on top of BBFO2 thin films under solar light showed the degradation of all pollutants in varying discoloration efficiencies, ranging from 81% (RhB) to 54% (OG), 53% (Violet), 47% (MO) and 43% (MB). Full article

Bismuth-based perovskite derivatives, (CH₃NH₃)₃Bi₂I₉ (MBI), are promising non-toxic light-absorbing materials widely used in various photoelectric devices because of their excellent stability. However, MBI-based perovskite solar cells (PSCs) are limited by poor film quality, and the performance of such a device is far behind that of lead-based PSCs. In this work, the crystal structure and morphological properties of MBI films were compared across different preparation methods. The two-step vapor-assisted method can prepare continuous dense MBI films because MBI crystal nucleation is induced by the BiI₃ seed layer. The MBI film grown by this method is better for the production of excellent PSCs compared to the film prepared by the solution method. The best photovoltaic device based on the MBI film could obtain a power conversion efficiency of 1.13%. An MBI device is stored in the glove box for 60 days, and the device’s performance is maintained at 99%. These results indicate that the vapor-assisted deposition of MBI films can be an effective method to improve the performance of bismuth-based planar PSCs. Full article

The experimental and theoretical study of photovoltage formation in perovskite solar cells under pulsed laser excitation at 0.53 μm wavelength is presented. Two types of solar cells were fabricated on the base of cesium-containing triple cation perovskite films: (1) Cs_x(FA_0.83MA_0.17)_(1−x)Pb(I_0.83Br_0.17)₃ and (2) Cs_x(FA_0.83MA_0.17)_(1−x)Pb_0.8Sn_0.2(I_0.83Br_0.17)₃. It is found that photovoltage across the solar cells consists of two components, U = U_ph + U_f. The first one, U_ph, is the traditional photovoltage arising due to laser radiation-induced electron-hole pair generation. The second one, U_f, is the fast component following the laser pulse and has a polarity opposite to that of U_ph. It is shown that the fast photovoltage component results from the laser radiation-caused heating of free carriers. The transient photovoltage measurements show that the values of the fast component U_f are nearly the same in both types of perovskite solar cells. The magnitude of the traditional photovoltage of mixed Pb-Sn perovskite solar cells is lower than that of Pb-based cells. Full article

The most common method of processing metal oxide and perovskite thin films in the laboratory is thermal annealing (TA), which is a constraint for the commercialization of large-scale perovskite solar cells. Here, we present a photonic curing (PC) process to produce fully photonically annealed perovskite cells—a fast process with well-controlled, short light pulses—to develop perovskite photovoltaic devices with high efficiency. We also demonstrate how to use the parameters of the photonic annealing system to control the optical, electrical, morphological, and structural properties of perovskite layers for photovoltaic device applications. The effect of PC treatment on the microstructure, granularity, and electronic properties was studied by scanning electron microscopy (SEM), photoluminescence (PL), and transient photocurrent (TPC). The degree of conversion of the perovskite precursor and its influence on the electronic structure have been identified. $\mathrm{S}\mathrm{n}{\mathrm{O}}_2$ and perovskite films were treated with a single pulse and produced PCE comparable to control samples treated by TA. Full article

Pinhole defects in thin films can significantly degrade their physical and chemical properties and act as sites for electrochemical corrosion. Therefore, the development of methods for the preparation of pinhole-free films is crucial. Electrodeposition, recognised for its efficiency and cost-effectiveness, shows great potential for applications in electrochemistry, biosensors, solar cells and electronic device fabrication. This review aims to elucidate the role of nucleation and growth models in understanding and optimising the electrodeposition process. Key parameters, such as crystal structure, orientation, surface morphology and defect control, are highlighted. In addition, the causes of pinhole defects, the effects of impurities and the potential and electrolyte composition on the deposited films are discussed. In particular, methods for minimising pinhole defects and two exemplary cases for a compact layer in relatively large-scale perovskite solar cells and nano-scale ultramicroelectrodes are discussed, exploring the influence of surface morphology, thickness and fabrication size under current common film preparation experiments. Finally, the critical aspects of controlled preparation, theoretical and technological advances, and the ongoing challenges in the field are provided. Full article

Thin transparent films of SnO₂ were obtained from aqueous–alcohol solutions of SnCl₄ on a flexible polyethylene terephthalate (PET) substrate by spray pyrolysis at 100 °C. The influence of the addition of aqueous ammonia to the film-forming solution on the different properties has been studied. Properties studied include surface morphology, phase composition and transparency of the formed films and the crystallization processes and band gap of the film material. It was found that the addition of aqueous ammonia causes the formation of skeletal crystals (NH₄)₂[SnCl₆] with a perovskite structure in the film structure. The resulting films are promising for use in the technology of manufacturing flexible solar cells. Full article

The rapid deployment of solar photovoltaic (PV) systems underscores their potential as vital clean energy solutions with reduced carbon emissions and increasingly competitive installation costs. This review examines PV waste management from a sustainable perspective, focusing on environmental impacts and technological advancements. Various solar cell technologies, including crystalline silicon, thin-film, and emerging third-generation cells like perovskite and organic photovoltaics, are analyzed for their life cycle and environmental effects. Effective disposal and recycling methods, such as physical separation and thermal and chemical treatments, are critically evaluated to mitigate ecological harm. The study highlights the need for improved recycling processes and sustainable practices to enhance the environmental benefits of PV systems. Future solutions call for better recycling techniques, increased efficiency in renewable materials, and comprehensive life cycle assessments to support the global transition to sustainable energy. This review aims to foster the integration of sustainable practices in the renewable energy sector, ensuring that PV systems contribute to a cleaner and more sustainable future. Full article

Wide-bandgap tin oxide (${\mathrm{SnO}}_2$) thin-films are frequently used as an electron-transporting layers in perovskite solar cells due to their superior thermal and environmental stabilities. However, its crystallization by conventional thermal methods typically requires high temperatures and long periods of time. These post-processing conditions severely limit the choice of substrates and reduce the large-scale manufacturing capabilities. This work describes the intense-pulsed-light-induced crystallization of ${\mathrm{SnO}}_2$ thin-films using only 500 $\mathsf{\mu }\mathrm{s}$ of exposure time. The thin-films’ properties are investigated using both impedance spectroscopy and photoconductivity characteristic measurements. A Nyquist plot analysis establishes that the process parameters have a significant impact on the electronic and ionic behaviors of the ${\mathrm{SnO}}_2$ films. Most importantly, we demonstrate that light-induced crystallization yields improved topography and excellent electrical properties through enhanced charge transfer, improved interfacial morphology, and better ohmic contact compared to thermally annealed (TA) ${\mathrm{SnO}}_2$ films. Full article

The scalable production of high-quality perovskite thin films is pivotal for the industrialization of perovskite thin film solar cells. Consequently, the solvent system employed for the fabrication of large-area perovskite films via coating processes has attracted significant attention. In this study, a solvent system utilizing a volatile solvent as the primary reagent has been developed to facilitate the rapid nucleation of volatile compounds. While adding the liquid Lewis base dimethylformamide (DMF) can help to improve the microstructure of perovskite films, its slow volatilization renders the crystal growth process uncontrollable. Based on the solvent system containing DMF and ethanol (EtOH), introducing a small amount of NH₄Cl increases the proportion of the intermediate phase in the precursor films. This not only results in a controllable growth process for the perovskite crystals but also contributes to the improvement of the film microstructure. Under the simulated illumination (AM1.5, 1000 W/m²), the photoelectric conversion efficiency (PCE) of the inverted solar cells has been improved to 20.12%. Furthermore, after 500 hours of continuous illumination, the photovoltaic device can retain 95.6 % of the initial, indicating that the solvent system is suitable for the scalable fabrication of high-quality FAPbI₃ thin films. Full article