Search Results (1,252)

Benefiting from the booming development of self-assembled monolayer (SAM) based hole-transporting materials, inverted perovskite solar cells (PSCs) have attained a certified power conversion efficiency (PCE) beyond 27.0%, exhibiting great potential for commercialization. However, conventional SAM molecules are prone to self-aggregation owing to their inherent molecular configurations, which readily induced defective and inhomogeneous deposition. In addition, state-of-the-art SAM-based hole-transporting layers are generally deposited in inert environments, while the ambient moisture is expected to further deteriorate the homogeneity of the SAM layers. In this work, a mixed-solvent system of ethanol/N,N-dimethylformamide (DMF) was adopted for the deposition of Me-4PACz SAMs in ambient conditions, which enables significant suppression of intermolecular aggregation in precursor solution and moisture-induced inhomogeneity. The high-quality homogeneous SAM-based hole-transporting layers, along with subsequently optimized perovskite buried interface properties, further empower a prominent increase in the PCE of inverted PSC devices up to 25.0%. Full article

The growing demand for efficient, stable, and environmentally friendly materials for next-generation optoelectronic and photovoltaic applications has attracted significant interest in double perovskite compounds. First-principles density functional theory (DFT) calculations were performed to systematically investigate the structural, mechanical, electronic, and optical properties of Ba₂MReO₆ (M = Li, Na, K, and Rb) double perovskites. Structural optimization confirms that all compounds crystallize in the cubic Fm3̅m symmetry. The thermodynamic and geometric stability of the series is checked with negative formation energies and tolerance factor analyses (t, μ, τ). Mechanical analysis confirms that all compounds are mechanically stable; Ba₂LiReO₆ is the stiffest, while Ba₂RbReO₆ shows moderate stiffness with the highest ductility. Furthermore, ab initio molecular dynamics (AIMD) simulations at room temperature confirm the dynamical stability of all compounds, with negligible fluctuations in total energy under thermal conditions. The calculated band structures using both GGA-PBE and HSE06 hybrid functionals reveal that all compounds possess indirect band gaps, with HSE06 values of 2.236 eV for Ba₂LiReO₆, 2.133 eV for Ba₂NaReO₆, 2.116 eV for Ba₂KReO₆, and 1.395 eV for Ba₂RbReO₆. Optical measurements indicate that it is highly polarizable by dielectric polarizability, has high absorption coefficients (approximately 10⁶ cm⁻¹), and has large optical conductivity in the UV, with large inter-band interactions between 2 and 4 eV. The suitable band gap and favorable optical characteristics suggest that Ba₂RbReO₆ is the most promising candidate for photovoltaic and solar-cell applications. Full article

The crystallization quality of a perovskite active layer is highly sensitive to processing conditions and plays a decisive role in determining the performance of perovskite solar cells (PSCs). Herein, we systematically investigate the synergistic effects of the antisolvent dripping time and annealing time on the active layer crystallization and device performance. By optimizing the chlorobenzene (CB) dripping time during spin coating, we find that the film prepared at 19 s exhibits the most compact and uniform morphology, together with enhanced crystallinity. On this basis, further optimization of post-annealing at 100 °C reveals that 30 min is most favorable for promoting grain growth and minimizing defect formation. As a result, the optimized device delivers a champion PCE of 24.43%, with a short-circuit density (J_sc) of 25.69 mA cm⁻², a V_oc of 1.14 V, and an FF of 83.20%. This work highlights the critical role of process-window engineering in governing perovskite crystallization and provides an effective route toward high-efficiency PSCs. Full article

Tin–lead halide perovskite is a promising narrow-bandgap absorber for high-performance perovskite solar cells. However, the easy oxidation of Sn²⁺ and the resulting defect formation still limit these films’ quality and photovoltaic performance. Tin fluoride (SnF₂) is widely used as an antioxidant additive in Sn-containing perovskites, but its optimal concentration remains strongly dependent on the specific perovskite composition. Herein, we systematically investigate the influence of SnF₂ concentration on the film quality and device performance of methylammonium-free Sn–Pb perovskite solar cells. By varying the SnF₂ content from 0 to 15% relative to SnI₂, we find that an appropriate amount of SnF₂ can effectively improve the surface morphology, enhance crystallinity, promote preferred crystal orientation, and suppress defect-assisted non-radiative recombination. In particular, the film with 10% SnF₂ exhibits the smoothest surface, with a reduced root-mean-square roughness, enhanced photoluminescence intensity, and a lower trap density compared with the control films. As a result, the optimized device delivers a champion power conversion efficiency of 19.15%, significantly outperforming the control device. This work demonstrates the importance of SnF₂ concentration optimization and provides a useful guideline for improving MA-free Sn–Pb perovskite solar cells. Full article

This work reports the results of a study on the optical, morphological, and structural properties of cesium lead bromide iodide mixed perovskite thin films (CsPbBr_3−xI_x), synthesized by sequential evaporation of precursors (CsBr, PbBr₂, PbI₂). First, the deposition conditions were optimized to obtain thin films predominantly composed of the pure CsPbBr₃ phase. Subsequently, the influence of partial substitution of Br⁻ by I⁻ on the film properties was investigated. Particular emphasis was placed on evaluating the effect of partial Pb²⁺ substitution by Zn²⁺ on the optical, morphological, electronic, and structural properties using optical transmittance, photoluminescence, scanning electron microscopy (SEM), X-ray diffraction (XRD), Urbach energy analysis, and density functional theory (DFT) calculations. Zn²⁺-doped CsPbBr_3−xI_x films were prepared by evaporating a ZnBr₂ layer onto the pre-deposited PbBr₂/PbI₂ precursor layers. It was found that Zn²⁺-doped inorganic CsPbBr_3−xI_x perovskite films exhibit enhanced crystallinity and improved surface morphology. Additionally, photoluminescence characterization confirms that non-radiative recombination decreases significantly, apparently due to a reduction in intrinsic defect density. The effect of Zn²⁺ doping on the power conversion efficiency of carbon-based planar solar cells was also evaluated. Collectively, Urbach energy, photoluminescence, and SEM analyses revealed that the optimal Zn²⁺ doping range for CsPbBr_3−xI_x perovskite films is ≤5%. Full article

CsPbI₂Br, an all-inorganic cesium–lead mixed-halide perovskite, has established itself as a leading contender for next-generation photovoltaics, owing to its near-optimal direct bandgap, exceptional thermal stability, and favorable optoelectronic characteristics. These attributes make it a versatile candidate for both high-efficiency single-junction devices and wide-bandgap top cells in tandem architectures with silicon or low-bandgap perovskites. However, the commercialization of CsPbI₂Br perovskite solar cells (PSCs) is severely hindered by inherent interfacial challenges, including halide segregation under operational stress, high density of interfacial defects, energy-level misalignment between the perovskite and charge transport layers (CTLs), and chemical incompatibility at hetero-interfaces. These factors limit power conversion efficiency (PCE) and long-term operational stability. Interface engineering has thus become the pivotal strategy to address these bottlenecks, enabling transformative improvements in device performance. This review comprehensively summarizes the state-of-the-art interface engineering strategies for CsPbI₂Br PSCs, including molecular passivation, construction of 2D/3D heterostructures, design of composite interlayers, and development of dopant-free, stable CTLs. The underlying mechanisms of defect passivation, non-radiative recombination suppression, energy-level alignment optimization, and ion migration inhibition are systematically elucidated. Furthermore, we discuss critical remaining challenges, including the trade-off between phase stability and optoelectronic quality, interfacial delamination due to thermal expansion mismatch, and scalable fabrication of interface-modified large-area devices. Finally, future research directions are proposed, emphasizing the development of multifunctional interfacial materials, all-inorganic interface architectures, in situ characterization combined with computational modeling, and integration into tandem photovoltaic systems. By consolidating current knowledge and highlighting promising frontiers, this review aims to guide the rational design of high-performance, stable, and commercially viable CsPbI₂Br PSCs, accelerating their role in the global transition toward renewable energy. Full article

This study examines the influence of device architecture and substrate materials on the external quantum efficiency (EQE) of high-performance solar cells. A diverse array of photovoltaic technologies was evaluated, including formamidinium lead iodide CH₅N₂PbI₃ (FAPI) perovskite cells and various silicon-based designs, such as Passivated Emitter and Rear Cell (PERC), Back Integrated Contact (BIC), and Bifacial structures. Quantum characteristics were determined through wavelength-dependent photocurrent measurements utilizing a precision monochromator system. Our results reveal that device structure is a primary determinant of charge carrier collection efficiency; specifically, Bifacial and PERCs achieved superior short-circuit current densities (J_sc) of 40.98 mA/cm² and 39.42 mA/cm², respectively. Notably, the EQE(λ) profile of Bifacial cells under n-side illumination exhibits a near-ideal rectangular shape, indicating an optimized spectral response throughout the operating spectrum. Furthermore, the analysis investigates the role of surface recombination velocity and the efficacy of advanced passivation layers—specifically Al₂O₃ and SiN_x—in enhancing quantum performance by mitigating recombination state density. Our findings demonstrate that the strategic integration of advanced passivation layers (Al₂O₃ and SiN_x) with optimized architectures, such as PERC and Bifacial designs, is paramount for maximizing charge carrier collection and achieving record-high current densities reaching 40.98 mA/cm². A comprehensive analysis of solar cell performance involves spectral response (SR) and external quantum efficiency (EQE) as functions of wavelength. Additionally, SR-based current density analysis enables more accurate evaluation of cell parameters than standard I–V characterization. Full article

Interfacial defect passivation has emerged as a critical strategy for mitigating non-radiative recombination losses in inorganic perovskite solar cells (PSCs). However, the distinct chemical environments at the bottom (hole-transport layer) and top (electron-transport layer) interfaces demand passivation agents with tailored functionalities—a principle that remains largely underexplored. Herein, we systematically employed two organic ammonium iodide salts, phenylethylammonium iodide (PEAI) and 2-thiophenemethylammonium iodide (ThMI), to separately modulate the bottom NiO_x/CsPbI₂Br and top CsPbI₂Br/PCBM interfaces of inverted PSCs with a configuration of ITO/NiO_x/CsPbI₂Br/PCBM/BCP/Ag. We reveal different interfacial modulation effects: bottom-interface modification by both PEAI and ThMI dramatically improves the fill factor (FF), with PEAI delivering a more pronounced enhancement due to improved interfacial contact and reduced series resistance. However, top-interface passivation effectively boosts the open-circuit voltage (V_oc), where ThMI exhibits superior voltage elevation capability over PEAI by neutralizing undercoordinated Pb²⁺ defects via its thiophene moiety. Capitalizing on this complementary selectivity, we construct an asymmetric dual-interface passivation architecture with PEAI at the bottom and ThMI at the top (ITO/NiO_x/PEAI/CsPbI₂Br/ThMI/PCBM/BCP/Ag), which synergistically enhances both FF and V_oc. Consequently, the optimized PEAI/ThMI device achieves a champion power conversion efficiency (PCE) of 15.44%, with a V_oc of 1.15 V, a J_sc of 16.34 mA/cm², and an FF of 82.15%, significantly outperforming the control device (11.79%). This work establishes a rational design paradigm for interface-specific passivation in inverted inorganic PSCs, highlighting the importance of molecular functionality in addressing distinct interfacial recombination pathways. Full article

The performance of inverted CH₃NH₃GeI₃ (MAGeI₃) perovskite solar cells incorporating both a hole transport layer (HTL) and an electron transport layer (ETL) was investigated using the Solar Cell Capacitance Simulator (SCAPS). Three candidate HTLs, including PEDOT:PSS, MoS₂, and WS₂, along with five ETLs including PCBM, TiO₂, IGZO, ZnO, and SnO₂, have been systematically evaluated. The analysis shows that WS₂ and SnO₂ provided the most favorable hole and electron transport, respectively. To improve device efficiency, the absorber layer thickness, defect density in MAGeI₃, doping levels of WS₂ and SnO₂, as well as the interface defect densities and the work function of indium tin oxide (ITO), have been systematically studied. The optimal absorber layer thickness is determined to be approximately 900 nm. The optimal doping density of both WS₂ and SnO₂ is 1 × 10¹⁹ cm⁻³. The MAGeI₃ layer should maintain a defect density as low as 1 × 10¹⁵ cm⁻³, and the defect densities at MAGeI₃ interfaces should remain at 1 × 10¹⁵ cm⁻². Additionally, an ITO work function of at least 5.2 eV is necessary to prevent the formation of a Schottky barrier at the ITO/WS₂ interface. The simulated power conversion efficiency (PCE) can reach 22.9% under these optimized conditions. Our simulation results offer a viable route to develop high-efficiency MAGeI₃ perovskite solar cells. Full article

Substoichiometric molybdenum oxide is widely utilized as a hole transport layer (HTL) in polymer solar cells and perovskite solar cells. In this study, the possibility of developing MoOx layers applicable as HTLs with different characteristics by magnetron sputtering from a MoO₃ target and annealing in dry nitrogen or air is explored. The optical transmission and reflection, optical band gap, FTIR and Raman spectra, crystallinity, conductivity, and work function of the films are studied depending on deposition and annealing conditions. The results demonstrate that it is possible to tune the properties of the obtained films with a view toward their application in solar cells. Full article

Modern photovoltaic technologies are increasingly evaluated not only in terms of power conversion efficiency and cost, but also with respect to resource origin, toxicity, recyclability, and overall life-cycle impacts. Within this broader sustainability framework, bio-based and bio-inspired materials derived from biomass or mimicking biological structures have emerged as promising candidates for a wide range of photovoltaic components, including active layers, interfacial modifiers, substrates, encapsulants, and natural dyes. This review provides a layer-by-layer overview of such materials implemented or proposed in dye-sensitized, organic, perovskite, biohybrid, and silicon solar cells, linking their molecular structures and optoelectronic properties to representative device performances and key degradation pathways. Cross-cutting challenges related to moisture and thermal stability, barrier performance, feedstock variability, and the risk of “greenwashing” are highlighted, emphasizing that sustainability claims must be supported by quantitative metrics such as life-cycle assessment, circularity indicators, and durability studies. Finally, we outline promising research directions in molecular engineering, hybrid biosynthetic architectures, and advanced encapsulation concepts that could enable bio-based materials to make a meaningful contribution to low-impact photovoltaic technologies. Full article

Organic–inorganic hybrid perovskites (OIHPs) have been widely used in fields such as solar cells, photodetectors, and light-emitting diodes due to their simple preparation by solution methods and excellent optoelectronic properties. In recent years, numerous scholars have delved deeply into the magneto-optical properties of perovskites and explored their potential applications in the magneto-optical field. Herein, we present the Faraday rotation characteristics of formamidinium lead bromide (Fabri₃) single crystals within the visible spectrum range. Firstly, FAPbBr₃ single crystals with high transparency and a size of 5.5 × 5.6 × 2 mm³ were prepared using the modified inverse temperature crystallization (MITC) method. The experimental results showed that the Verdet constant of FAPbBr₃ single crystal at 565 nm was up to 531.6 rad/(T·m). Furthermore, the FAPbBr₃ single crystal showed similar or an even higher Verdet constant when compared with the mature magneto-optical material TGG single crystal commonly used in the industry. The thermal simulation results of the FAPbBr₃ single crystal show low temperature dependence which achieves about 90% isolation transparency with a magnetic field of 0.35 T for 625 nm. This study demonstrates the outstanding Faraday rotation properties of FAPbBr₃ single crystals, thereby offering promising prospects for the development of perovskite materials in non-reciprocal devices such as optical isolators and optical circulators. Full article

Conventional machine learning models for perovskite solar cells predict photovoltaic parameters independently, disregarding the physical constraint $\mathrm{PCE}=V_{oc}\times J_{sc}\times \mathrm{FF}/100$. This approach can yield mutually incompatible predictions for the four parameters, a failure mode that has not been hitherto quantified in the perovskite solar cell literature. This paper proposes a multi-head neural network with a shared backbone, physics-guided feature construction, and task-specific prediction heads, and validates it on 7176 SCAPS-1D simulations across 12 perovskite compositions. When benchmarked against architecturally matched single-task baselines, the multi-task model, optimized via 5-fold cross-validation, achieves $R^2$ values of at least 0.994 for all four targets, with cross-fold standard deviations of 0.001. In particular, fill factor prediction improves from $R^2=0.617\pm 0.254$ (single-task) to $0.994\pm 0.001$ (multi-task), a 233-fold reduction in cross-fold standard deviation. Application of a physical consistency metric developed in this work reveals that 36.5% of single-task predictions exceed a 2 PCE-unit implausibility threshold, compared to only 0.01% for the multi-task model. The multi-task model outperforms the single-task baseline in all 20-fold target comparisons, with large effect sizes (Cohen’s $d=1.33$–$8.93$). These results confirm multi-task learning as an effective approach for achieving robust, stable, and internally consistent predictions in simulation-based photovoltaic virtual screening. Full article

This review evaluates the role of advanced materials in optimizing the efficiency, sustainability, and market integration of solar photovoltaic (PV) technologies. Our work bridges insights from both mature (crystalline silicon (c-Si)) and novel perovskites (PSs), organic photovoltaics (OPVs), and quantum dot solar cell (QDSC) materials, thereby providing a unified view of the present and the future of PV research. We highlight the key breakthroughs for the different material classes, describing their unique features, record performance, and contribution to lowering the cost of solar energy. In particular, while some progress has been made, we recognize that challenges such as the stability of the device under varying environmental conditions, the environmental impact of the materials, and the scalability of the manufacturing processes are still there. In conclusion, we give an overview of the research topics that can pave the way for the future. We support the formation of hybrid structures, the finding of lead-free alternatives, multi-junction architectures, and integrated solutions that not only help to overcome the current limitations but also facilitate the global energy transition. Full article

The efficiency of perovskite solar cells has increased to a certified value of 27% over the past decade, benefiting from the superior properties of metal halide perovskite materials. However, their long-term operational stability is still far inferior to that of commercial crystalline silicon solar cells. A key source of this instability is field-driven ion migration in vertical architectures, along with the consequent degradation at the absorber–electrode interfaces. Compared with the widely investigated vertical structures, back-contacted (BC) perovskite solar cells—wherein both electrodes are positioned on the same side of the absorber—offer a unique route to suppress interfacial ion migration and thereby enhance long-term device stability. These advantages are especially pronounced when combined with single-crystal perovskites, which possess low charge trap densities, long carrier diffusion lengths, and high bulk ion migration barriers. Unfortunately, only a handful of research groups have participated in the development of single-crystal BC perovskite solar cells; thus, the advancement of this area lags far behind that of its vertical counterpart. Therefore, a review that discusses the recent developments and challenges of single-crystal BC perovskite solar cells is urgently required to provide guidelines for this emerging field. In this progress report, we first introduce the main growth methods of single-crystal wafers compatible with BC architectures, followed by an outline of the developmental history of BC perovskite solar cells. Finally, the core bottlenecks facing single-crystal BC devices and corresponding optimization strategies are discussed in detail. Full article