Photovoltaic Conversion Efficiency Research Articles

Improving Thermal Stability of High-Efficiency Methylammonium-Free Perovskite Solar Cells via Chloride Additive Engineering.

Tin dioxide (SnO2), in perovskite solar cells (PSCs), stands out as the material most suited to the electron transport layer (ETL), yielding advantages with regard to ease of preparation, high mobility, and favorable energy level alignment. Nonetheless, there is a chance that energy losses from defects in the SnO2 and interface will result in a reduction in the Voc. Consequently, optimizing the interfaces within solar cell devices is a key to augmenting both the efficiency and the stability of PSCs. Herein this present study, we introduced butylammonium chloride (BACl) into the SnO2 ETL. The resulting optimized SnO2 film mitigated interface defect density, thereby improving charge extraction. The robust bonding capability of negatively charged Cl- ions facilitated their binding with noncoordinated Sn4+ ions, effectively passivating defects associated with oxygen vacancies and enhancing charge transport within the SnO2 ETL. Concurrently, doped BA+ and Cl- diffused into the perovskite lattice, fostering perovskite grain growth and reducing the defects in perovskite. In comparison to the control device, the Voc saw a 70 mV increase, achieving a champion efficiency of 22.86%. Additionally, following 1000 h of ambient storage, the unencapsulated device based on SnO2 preburied with BACl retained around 90% of its initial photovoltaic conversion efficiency.

Improved performance of ternary organic solar cells based on both bulk and pseudo-planar heterojunction active layer

The high photovoltaic conversion efficiency (PCE) of ternary organic solar cells (OSCs) based on PTB7-Th, PC71BM and IEICO-4F material is obtained, the short-circuit current density (J SC), fill factor (FF), and open-circuit voltage is 25.90 mA cm−2, 73.20% and 0.71 V, respectively. PCE is as high as 13.53%. It is the highest PCE of ternary OSCs based on PTB7-Th, PC71BM and IEICO-4F materials for all we know. The narrow bandgap material of IEICO-4F is deposited on PTB7-Th:PC71BM bulk heterojunction (BHJ) by layer-by-layer process. We constructed the dual bandgap active layer both BHJ and pseudo-planar heterojunction (P-PHJ), it could be defined as ternary BHJ/P-PHJ of OSCs. This type of OSCs is not only the complementary bandgap material of the active layer, but also increasing the donor/acceptor (D/A) interface. The excitons generation and collection of the device are increased leading a higher J SC and FF. The semitransparent OSCs (ST-OSCs) is prepared by varying the thickness of Ag electrode and PCE can reach 9.70%, and the average visible light transmittance and light use efficiency of ST-OSCs are improved effectively.

Filtered spectrum modeling of high-performance perovskite tandem solar cells: Tailoring absorber properties and electron/hole transport layers for 31.55 % efficiency

In this study, the perovskite tandem solar cell (TPSC) has been accomplished using SCAPS-1D. The present study focuses on comprehensive exploration and detailed optimization using various strategies constructing a tandem device. To calculate high photovoltaic power conversion efficiency (PCE), the numerical analysis has been carried out for a wide-bandgap halide (WBH) FA0.75Cs0·25Pb(I0·8Br0.2)3 of bandgap 1.67eV and a Pb–Sn based narrow-bandgap halide (NBH) FA0.7MA0.3Pb0·5Sn0·5I3 of bandgap 1.22eV as absorber layer in top-cell (TCELL) and bottom-cell (BCELL) respectively. The WBH has huge potential as a front light absorber and the NBH based BCELL provides stability and high performance by accepting high and low energy photons respectively. This method mitigates thermalization and non-absorbed photon loss which results in the growth in PCE. The proposed work demonstrates the impact of active-layer thickness along with defect density on the solar-cell parameters. It has been observed that defect density is low for the optimal performance. An investigation for various electron transport medium (ETMs) and hole transport medium (HTMs) has been done to secure an optimum performing TCELL as well as BCELL. Using filtered-spectrum study along with current-matching method, every PV metric parameter has been analyzed after their deployment into tandem configuration. The numerical investigation has shown promising photovoltaic parameters with aa high open circuit voltage (VOC) of 2.33 V, a short circuit current density (JSC) of 17.07 mA/cm2, a fill factor (FF) of 79.34 % and PCE of 31.55 % in tandem configuration.

The Key Role of Hole Transport Layer in Boosting Performance of Two‐Dimensional Perovskite Solar Cells

Although currently in the nascent stages of research and development, two‐dimensional perovskite solar cells have showcased remarkable promise as the robust and efficient solar cell technology. Anticipated progressions and refinements in this domain are poised to establish two‐dimensional perovskite cells as instrumental catalysts in shaping the trajectory of renewable energy, heralding transformative breakthroughs. The hole transport layer (HTL) plays an irreplaceable role in the charge carriers’ transport and interface effects in two‐dimensional perovskite devices. This review starts with the structural characteristics of two‐dimensional perovskite solar cells. The influence of the intrinsic characteristics of the perovskite active layer itself and the interaction of the perovskite/transport layer contact interface are analyzed. This discussion delves into the impact of intrinsic quantum confinement and the dielectric effect within the two‐dimensional perovskite structure on photovoltaic conversion efficiency. It also explores the energy level alignment between the clathrate active layer and the transport layer. The significance of the HTL is emphasized, particularly regarding crystalline control, phase distribution, and interface passivation. Additionally, the crucial role of efficient carrier transport between the active layer and the transport layer is thoroughly examined.

Unveiling Advancements: Trends and Hotspots of Metal-Organic Frameworks in Photocatalytic CO2 Reduction.

Metal-organic frameworks (MOFs) are robust, crystalline, and porous materials featured by their superior CO2 adsorption capacity, tunable energy band structure, and enhanced photovoltaic conversion efficiency, making them highly promising for photocatalytic CO2 reduction reaction (PCO2RR). This study presents a comprehensive examination of the advancements in MOFs-based PCO2RR field spanning the period from 2011 to 2023. Employing bibliometric analysis, the paper scrutinizes the widely adopted terminology and citation patterns, elucidating trends in publication, leading research entities, and the thematic evolution within the field. The findings highlight a period of rapid expansion and increasing interdisciplinary integration, with extensive international and institutional collaboration. A notable emphasis on significant research clusters and key terminologies identified through co-occurrence network analysis, highlighting predominant research on MOFs such as UiO, MIL, ZIF, porphyrin-based MOFs, their composites, and the hybridization with photosensitizers and molecular catalysts. Furthermore, prospective design approaches for catalysts are explored, encompassing single-atom catalysts (SACs), interfacial interaction enhancement, novel MOF constructions, biocatalysis, etc. It also delves into potential avenues for scaling these materials from the laboratory to industrial applications, underlining the primary technical challenges that need to be overcome to facilitate the broader application and development of MOFs-based PCO2RR technologies.

The surface effect of chlorinated mesoscopic TiO2 in printable carbon-based perovskite solar cells

Printable HTM-free (HTM = hole-transporting material) mesoporous carbon-based perovskite solar cells (C-PSCs) are one of the most promising technologies. In this study, a high-quality chlorinated mesoscopic TiO2 (m-TiO2) film was obtained by hydrochloric acid (HCl) wet chemical process and applied in C-PSCs based on TiO2/ZrO2/(5-AVA)x(MA)1-xPbI3/C structures. Experimental results show that the PCE of chlorinated m-TiO2 C-PSCs greatly improved. Based on (5-AVA)x(MA)1-xPbI3, C-PSCs with TiO2 ETL treated with HCl aqueous solution achieved an average photovoltaic conversion efficiency of 9.36 %, which is an increase of 7.96 % in comparison with the efficiency of the device using unmodified TiO2 ETL, while the Voc and the Jsc were increased by 3.63 % and 2.63 %, respectively. In a 30-day aging test, C-PSCs based on (5-AVA)x(MA)1-xPbI3 and TiO2-HCl 1 exhibited excellent stability under ambient air conditions.

Excellent visible light absorption and ultra-high photoelectric conversion efficiency of two-dimensional (MoSe2)x(MoSTe)1-x mosaic heterostructures

Solar cells are a promising and potentially sustainable energy technology due to their cost-effectiveness, eco-friendliness, and capacity for integration into pliable apparatuses. Developing new photovoltaic materials to achieve higher photovoltaic conversion efficiency is a hot topic in the field of solar cells. In this work, the electronic structures and optical properties of two-dimensional (MoSe2)x(MoSTe)1-x mosaic heterostructures have been studied by density functional theory. Our results show that the mosaic heterostructures retain semiconductors with tunable band gap of 1.14–1.53 eV. With the augmentation of MoSe2 concentration in the mosaic heterostructures, the band gap of the materials has gradually increased. Besides, the mosaic heterostructures exhibit excellent optical absorption in the visible light region. Furthermore, the maximum theoretical photoelectric conversion efficiency of (MoSe2)0.80(MoSTe)0.20 mosaic heterostructure can reach 32.36 %. The tunable band gap, excellent light absorption, and ultra-high photoelectric conversion efficiency of (MoSe2)x(MoSTe)1-x mosaic heterostructures make them candidates for new nanocrystalline thin-film solar cells.

Improving vapor condensation via copper foam in capillary-fed photovoltaic membrane distillation

The photovoltaic conversion efficiency of solar cells is significantly constrained by temperature rise. Photovoltaic membrane distillation (PVMD) offers a promising solution for simultaneous solar cell cooling and clean water production. However, the present PVMD system is confronted with the challenge of attaining high cooling efficiency and water production sans reliance on fossil fuels. In this work, a novel and zero-carbon PVMD system is introduced and optimized. One notable improvement is the transportation of feedwater to the backside of the solar cell using capillarity instead of a pumping system. Additionally, a porous copper foam condenser with a rough surface is introduced to the PVMD system. This rough surface creates more nucleation sites for rapid vapor condensation, resulting in a water productivity increase from 0.23 to 0.43 kg m−2 h−1 under 1 sun (=1 kW m−2) irradiation. Furthermore, a 5 cm × 5 cm solar cell demonstrates a temperature decrease from 59.9 to 38.3 °C, accompanied by a voltage enhancement from 2.18 to 2.39 V. This work offers an effective strategy for lowering the operational temperature of solar cells and enhancing the overall utilization efficiency of PVMD devices.

Integration Device of Super-Capacitors with Dye-Sensitized Solar Cells

Integration Device of Super-Capacitors with Dye-Sensitized Solar Cells

Effects of Several Auxiliary Acceptors and Anchoring Groups on Charge Transfer and Photophysical Properties of D-A-π-A Type DSSCs: A DFT Study.

In this paper, we performed theoretical studies on the twelve D-A-π-A type organic dyes (G-1 ~ G-3, M-1 ~ M-3, J-1 ~ J-3, and S-1 ~ S-3) with 9-phenylcarbazole as the electron donor in anticipation of the application of these dyes in dye-sensitized solar cells (DSSCs). DFT and TD-DFT methods are applied to investigate in detail the molecular geometries, frontier molecular orbitals (FMOs), absorption spectra, charge density difference (CDD), and transition density matrix (TDM) of several dyes. The results show that the M-series (M-1 ~ M-3) dyes have the largest dihedral angles between the electron donor and the auxiliary acceptor and also has the largest energy gaps in HOMO-LUMO orbitals, which greatly reduces the charge transfer efficiency. Finally, the UV-Vis absorption spectra inferred that the anchoring groups modified with o-nitrobenzoic acid (G-3, M-3, J-3, S-3) can red-shift the absorption peaks of the dyes, which results in higher light-harvesting efficiency and improves the power conversion efficiency of DSSCs. Overall, all of these dyes contribute to the improvement of photovoltaic power conversion efficiency and have potential for application in DSSCs devices.

Optimal interfacial engineering with different bifunctional alkylamine sulfonates for efficient perovskite solar cells

Perovskite solar cells have gradually become the most attractive alternative for next-generation photovoltaic devices due to their excellent photovoltaic conversion efficiencies and low manufacturing costs. Defect engineering is an essential topic for improving the performance of perovskite devices. In this study, we utilize a bifunctional alkylamine sulfonate to modify the perovskite interfaces. The TsO− of sulfonates coordinates with Pb2+, while –NH2 of alkylamine forms hydrogen bonds with iodine, which reduces charge recombination and improves energy level arrangement. The molecular size and the alkylamine's dielectric constant significantly influence the interface modification performance. For the champion device with BATsO treatment, there is an enhancement in both the fill factor and the open-circuit voltage, resulting in a power conversion efficiency (PCE) of 23.53%. After 400 h of working condition, the device maintains roughly 90.40% of its initial efficiency. Therefore, this study postulates that modifying bifunctional alkylamine sulfonates could effectively enhance the PSC's performance.

Tuning Surface Defect States in Sputtered Titanium Oxide Electron Transport Layers for Enhanced Stability of Organic Photovoltaics.

Nonfullerene acceptors (NFAs) have dramatically improved the power conversion efficiency (PCE) of organic photovoltaics (OPV) in recent years; however, their device stability currently remains a bottleneck for further technological progress. Photocatalytic decomposition of nonfullerene acceptor molecules at metal oxide electron transport layer (ETL) interfaces has in several recent reports been demonstrated as one of the main degradation mechanisms for these high-performing OPV devices. While some routes for mitigating such degradation effects have been proposed, e.g., through a second layer integrated on the ETL surface, no clear strategy that complies with device scale-up and application requirements has been presented to date. In this work, it is demonstrated that the development of sputtered titanium oxide layers as ETLs in nonfullerene acceptor based OPV can lead to significantly enhanced device lifetimes. This is achieved by tuning the concentration of defect states at the oxide surface, via the reactive sputtering process, to mitigate the photocatalytic decomposition of NFA molecules at the metal oxide interlayers. Reduced defect state formation at the oxide surface is confirmed through X-ray photoelectron spectroscopy (XPS) studies, while the reduced photocatalytic decomposition of nonfullerene acceptor molecules is confirmed via optical spectroscopy investigations. The PBDB-T:ITIC organic solar cells show power conversion efficiencies of around 10% and significantly enhanced photostability. This is achieved through a reactive sputtering process that is fully scalable and industry compatible.

Case study of variable speed photovoltaic direct-driven ice-storage air conditioning system in Wuhu

In order to meet the contradiction between the growing demand for refrigeration and energy scarcity, this paper proposes a novel photovoltaic ice storage air conditioning system. The system is directly driven by a photovoltaic array. The performance of the system was studied through experiments, and a mathematical model was constructed for comparative verification. The experimental results show that the daytime cooling COP of the system is 1.18, the photovoltaic conversion efficiency is 6.29 %, and the nighttime cooling time is 9 h, which basically meets the cooling needs. Through simulation, the performance of the system was optimized, and the results showed that an increase in the initial water volume and temperature of the ice storage tank would increase the cooling COP; the spacing between evaporator pipes increased from 45 mm to 60 mm, resulting in a 7.11% increase in COP; the optimal spacing between evaporator fins is 9 mm, which improves performance by 9.11 %.

CdSe nanostructured thin film by electrophoretic deposition for quantum dots sensitized solar cell.

Cadmium selenide (CdSe) quantum dots (QDs) with different size, 2.5 and 3.2 nm, were successfully deposited on mesoporous titanium dioxide (TiO2) (Degussa-P25) nanostructures by electrophoretic deposition method (EPD) at the applied voltage 100 V for 120 s deposition time. In this study, the morphology of CdSe films deposited by EPD and the performance of the film when assembled into a solar cell were investigated. From the field emission scanning electron microscopy cross-section, the thickness of the CdSe nanoparticles with size 2.5 nm films were 3.4 and 3.0μm for CdSe 3.2 nm nanoparticles film. The structure of 2.5 nm is denser than compare of 3.2 nm CdSe nanoparticles. From UV visible spectroscopy, the band gap calculated for 2.5 nm CdSe nanoparticles is 2.28 eV and for 3.2 nm is 2.12 eV. Photovoltaic characterization was performed under an illumination of 100 mW cm-2. A photovoltaic conversion efficiency of 1.81% was obtained for 2.5 nm CdSe and 2.1% was obtained for 3.2 nm CdSe nanoparticles. This result shows that the photovoltaic efficiency is dependent on CdSe nanoparticle size.

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.

Suppress energy loss to boost power conversion efficiency of organic photovoltaics with linear side chains modulation

The high energy loss (Eloss) in organic solar cells (OSCs) is being the one of major problem, which limit the power conversion efficiency (PCE) of OSCs. In this work, we designed and synthesized three perylene diimide (PDI)-based Acceptor’-Donor-Acceptor-Donor- Acceptor’ (A′-DAD-A′) small molecules namely anti-PDFC-Cx (C8, C10, and C12) by changing the length of linear chains on IDT cores to investigate how the length of linear side chain affects Eloss and the power conversion efficiencies (PCEs) of OSCs. The optical energy bandgap and stacking mode for three anti-PDFC-Cx (C8, C10, and C12) remain the same, which were not influenced by the different lengths of side chains. Increasing the length of side chains on IDT cores from C8 to C10 and C12 would improve the PCE of PM6: anti-PDFC-Cx based devices from 11.52% to 12.43% and 12.27%, particularly the Voc increasing from 0.98 V of anti-PDFC-C8 and 1.00 V of anti-PDFC-C10 to 1.02 V of anti-PDFC-C12. Eloss analysis indicated the value of Eloss reduced as the length increases from C8, to C12. These results demonstate linear side chain engineer is an effective method to reduce Eloss and realize high PCE on the bases of not modulating the stacking mode of acceptor.

Research Progress in Facility Agriculture and Lighting by Bibliometric Analysis Based on CiteSpace

Given the pressures of internation-al market competition, the dual constraints of domestic resources and the environment, and the uncertainties posed by climate change, bolstering agricultural infra-structure construction is a realistic demand and a crucial approach for implementing emerging grain security strat-egies, particularly in developing countries. Facility agriculture is characterized as a modern agricultural production mode that improves or creates favorable environmental conditions within a specific locality. With the rapid expansion of large-scale facility agriculture, there has been an increased demand for various types of energy, including electricity, gas, cold, and heat. Agricultural lighting equipment used in facility agriculture is a modern agricultural technique that applies engineering technology to regulate light supplementation in the production process. Facility lighting offers several advantages over traditional methods, such as higher photovoltaic conversion efficiency, adjustable spectrum, high photosynthetic efficiency, energy efficiency, environmental friendliness, long lifespan, monochromatic light, cold light source, and compact size. Promoting national food security, carbon neutrality, returning farmland to forests, and implementing low-carbon green agricultural policies all contribute to the favorable use of facility agriculture lighting. This study aims to provide a systematic summary of the relevant research conducted in the past decade using Citespace software. The advantage of facility agriculture for carbon sequestration capacity can effectively reduce net carbon emissions from facility agricultural production activities. In addition, the combination of agriculture and the Internet of Things can effectively improve agricultural production efficiency and economic returns. Combining artificial intelligence and other technologies with facility agriculture engineering, based on multi-source data fusion, intelligent early warning for facility agriculture energy internet can be used to prevent agricultural meteorological disasters. More importantly, it helps maintain global food security, eliminate hunger, and reduce economic inequality. The findings of this study will contribute to a deeper understanding of agricultural lighting equipment, serving as a new theoretical foundation for achieving agricultural emission reduction targets and promoting agricultural technical cooperation.

C2DEM-YOLO: improved YOLOv8 for defect detection of photovoltaic cell modules in electroluminescence image

ABSTRACT Photovoltaic (PV) cell modules are the core components of PV power generation systems, and defects in these modules can significantly affect photovoltaic conversion efficiency and lifespan. Electroluminescence (EL) testing is a method used to detect defects during the production process of these modules. To address the issue of low defect detection accuracy caused by the complex background and large-scale variations of EL images, we propose an object detection network named C2DEM-YOLO to improve the accuracy of defect detection. Firstly, a deep-shallow feature extraction module called C2Dense is designed to replace the C2f module in the YOLOv8’s backbone. Secondly, a cross-space multi-scale attention(EMA) is introduced after C2Dense to apply pixel-level attention to the extracted features, which suppresses background information while enhancing useful features for defect detection. Finally, by replacing CIoU with Inner-CIoU, we introduce auxiliary regression boxes to improve the accuracy of detection and the generalisation ability of the model. Experimental results show that C2DEM-YOLO achieves an average precision of 92.31% on the PVEL-AD dataset, which has 2.41%, 1.93%, and 1.56% improvement compared to YOLOv5s, YOLOv8n, YOLOv8s, respectively. Moreover, on our self-built dataset, the mAP@0.5 and mAP@0.5:0.95 of C2DEM-YOLO are improved by 1.42% and 1.46% compared to YOLOv8n, reaching 84.07%.

Exploring mc‐Silicon Wafers: Utilizing Machine Learning to Enhance Wafer Quality Through Etching Studies

AbstractThis paper provides a method for improving the photovoltaic conversion efficiency and optical attributes of silicon solar cells manufactured from as‐cut boron doped p‐type multi‐crystalline silicon wafers using acid‐based chemical texturization via machine learning. A decreased reflectance, which can be attained by the right chemical etching conditions, is one of the key elements for raising solar cell efficiency. In this work, the mc‐Silicon wafer surface reflectance is obtained under (<2%) after optimization of wet chemical etching. The HF + HNO3 + CH3COOH chemical etchant is used in the ratio 1:3:2 at different conditions of the etching duration of 1 min, 2 min, 3 min, and 4 min, respectively. The as‐cut boron doped p‐type mc‐silicon wafers are analysed with ultraviolet–visible spectroscopy, optical microscopy, Fourier transforms infrared spectroscopy, thickness profilometer, and scanning electron microscopy before and after etching. The chemical etching solution produces good results in 3 min etched wafer, with a reflectivity value of <2%.The reflectivity and optical images are inputs to the convolutional neural network model and the linear regression model to obtain the etching rate for better reflectivity. The classification model provides 99.6% accuracy and the regression model results in the minimum mean squared error (MSE) of 0.062.

Dark Current Reduction and Performance Improvements in Graphene/Silicon Heterojunction Photodetectors Obtained Using a Non-Stoichiometric HfOx Thin Oxide Layer.

Graphene/silicon heterojunction photodetectors suffer from a high dark current due to the high surface states and low barrier height at the interface, which limits their application. In this study, we introduce an HfOx interfacial layer via magnetron sputtering to address this issue. With this new structure, the dark current is reduced by six times under a bias voltage of -2 V. Under 460 nm illumination, the responsivity is 0.228A/W, the detectivity is 1.15 × 1011 cmHz1/2W-1, and the noise equivalent power is 8.75 × 10-5 pW/Hz1/2, demonstrating an excellent weak light detection capability. Additionally, the oxygen vacancies in the HfOx interfacial layer provide a conductive channel for charge carriers, resulting in a 2.03-fold increase in photocurrent and an external quantum efficiency of 76.5%. The photodetector maintains good photoresponse ability at a low bias voltage. This work showcases the outstanding performance of HfOx films as interfacial layer materials and provides a new solution for high-performance photodetectors, as well as a new path to improve the photovoltaic conversion efficiency of solar cells.