Efficiency Improvement Of Solar Cells Research Articles

Simulation and efficiency improvement of perovskite solar cells using optimized carbon nanotube charge collector and molybdenum trioxide layer

Simulation and efficiency improvement of perovskite solar cells using optimized carbon nanotube charge collector and molybdenum trioxide layer

Silicon solar cell efficiency improvement employing electrostatically assembled polyelectrolyte–quantum dot multilayers

Down-shifting (DS) has proven to be an effective technique to address thermalization losses in photovoltaic devices. It involves the modification of the incident solar spectrum by luminescent species to better suit solar cell’s optimal absorption regions. Despite the number of favorable characteristics of quantum dots (QDs) as DS materials, their incorporation into highly ordered close-packed films remains the major drawback of QD-based DS applications. This limitation can be overcome by the sequential integration of QDs into a multilayered film via the layer-by-layer assembly technique, that allows the precise control of composition and thickness. The experimental results discussed herein indicate that upon optimization employing a model-assisted design approach, the spectral response of a silicon solar cell benefits from the down-shifting and antireflection capabilities of the QD film, as evinced by their quantum efficiency. For the optimum design, the incorporation of QDs triggered an increment of 26.1% in the power conversion efficiency driven by an increase of 29.2% in the short circuit current density. The controlled assembly of QD multilayers offers unique opportunities in light harvesting for new hybrid photovoltaic technologies.

Enhanced Conversion Efficiency in MAPbI3 Perovskite Solar Cells through Parameters Optimization via SCAPS-1D Simulation

In this study, various factors affecting the efficiency of the MAPbI3 perovskite solar cell (PSC) were analyzed using the SCAPS-1D simulation program. The basic device analyzed in this study had a structure of ITO/TiO2/MAPbI3/Cu2O/Au. The thickness of each layer (electron transport layer (ETL), perovskite absorption layer (PAL), and hole transport layer (HTL)), PAL defect density and interface defect density were investigated as parameters. The optimized parameters that yielded the highest light conversion efficiency were an ETL (TiO2) thickness of 100 nm, a PAL (MAPbI3) thickness of 1300 nm, an HTL (Cu2O) thickness of 400 nm, a PAL defect density of 1014 cm−3, and an interface defect density of 1013 cm−3 for both absorber/ETL and absorber/HTL interfaces. The optimized PSC exhibited a maximum efficiency of 19.30%. These results obtained in this study are expected to contribute considerably to the optimization and efficiency improvement of perovskite solar cells using inorganic charge-carrier transport layers.

Oriented Molecular Bridge Constructs Homogeneous Buried Interface for Perovskite Solar Cells with Efficiency Over 25.3.

Buried interface optimization matters the efficiency improvement of planar perovskite solar cells (PSCs), and the molecular bridge is reported to be an effective approach. Herein, a molecular bridge is constructed at buried interface using 4-chloro-3-sulfamoylbenzoic acid (CSBA), and its preferred arrangement is systematically investigated. It is elucidated that the CSBA molecular is prone to be orientationally absorbed on TiO2 surface through COOH-Ti, and then connect with perovskite through S═O-Pb, resulting in a feasible oriented molecular bridge. Contributing to the passivated interfacial defects, optimized interfacial energy level, and released perovskite tensile stress, resulting from the oriented CSBA molecular bridge, the PSCs with an active area of 0.08 cm2 achieve a certified power conversion efficiency (PCE) of 25.32%, the highest among the TiO2-based planar PSCs. Encouragingly, the PSCs with an active area of 1 cm2 achieve a champion PCE of 24.20%, significantly promoting the efficiency progress of large-area PSCs. In addition, the PSCs with oriented CSBA molecular bridge possess enhanced stability, the unencapsulated PSCs can maintain ≈91% and ≈85% of their initial PCE after 3000 h aging under ambient condition and 1200 h aging under exposure to UV irradiation.

Transient Photocurrents and Defect States in Hierarchically Structured ZnO Nanowires

ZnO‐nanostructured thin films can be used as electron transport layers in ordered heterojunction quantum‐dot solar cells. An increased interface between electron and hole‐transporting layers allows for a fast separation of the electron–hole pairs preventing their recombination. Consequently, an improvement of the overall solar cell efficiency is expected. ZnO hierarchical nanorod thin films can provide the desired increase in interface area. In this work, their properties are studied and compared with simple ZnO nanorod films. The ZnO nanorod films are synthesized hydrothermally by placing the quartz/indium‐tin‐oxide substrates in a solution of zinc nitrate hexahydrate and sodium hydroxide at 90 °C. Hierarchical structures are obtained through a second deposition step. Scanning electron microscopy is used to characterize the size and shape of the nanorods. Simple ZnO films display hexagonal nanorods with a diameter of around 150 nm while hierarchical films show additional 40 nm diameter nanorods growing on the side surfaces of the primary 150 nm nanorods. Optical transmittance spectroscopy reveals a bandgap around 3.35 eV. Current–voltage measurements in the high‐field regime of 104 V cm−1 are used to determine the density of trap states Nt through the application of trap‐filled limit current theory.

Gold nanostructures/quantum dots for the enhanced efficiency of organic solar cells.

Incorporating gold nanoparticles (AuNPs) into organic solar cell (OSC) structures provides an effective means to manipulate light-matter interactions. AuNPs have been used as plasmonic-enhancement and light-trapping materials in OSCs and exhibit diverse single and mixed morphologies. Substantial near-field enhancement from metal periodic structures has consistently demonstrated high enhancement in solar cell efficiency. Additionally, coupling with atomic gold clusters in the form of gold quantum dots holds promise for light harvesting through fluorescence phenomena. The configured devices optimize light utilization in OSCs by considering factors such as the morphology, position, and hybridization of localized surface plasmon resonance, propagating surface plasmon resonance, and fluorescence phenomena. This optimization enhances light absorption, scattering, and efficient trapping facilitated by gold nanostructures/quantum dots. The configured setup exhibits multiple effects, concurrently improving plasmonic and fluorescence responses under solar irradiation, thereby enhancing energy conversion performance. Integrating plasmonic nanostructures with OSCs can address fundamental issues, providing opportunities to enhance the light-absorption intensity and charge transfer efficiency at intra and intermolecular levels. This comprehensive review demonstrates that the greatest improvement in solar cell efficiency exceeded 30% compared with the reference cells.

Modulation of intermolecular interactions in hole transporting materials for improvement of perovskite solar cell efficiency: a strategy of trifluoromethoxy isomerization

A trifluoromethoxy isomerization strategy to modulate intermolecular interactions is proposed to balance the intermolecular interactions of hole transport materials and their interface interactions with perovskites.

Reducing the Open-Circuit Voltage Loss of PbS Quantum Dot Solar Cells via Hybrid Ligand Exchange Treatment.

The interface VOC loss between the active layer and the hole transport layer (HTL) of lead sulfide colloidal quantum dot (PbS-CQD) solar cells is a significant factor influencing the efficiency improvement of PbS colloidal quantum dot solar cells (PbS-CQDSCs). Currently, the most advanced solar cells adopt organic P-type HTLs (PbS-EDT) via solid-state ligand exchange with 1,2-ethanedithiol (EDT) on the CQD top active layer. However, EDT is unable to altogether remove the initial ligand oleic acid from the quantum dot surface, and its high reactivity leads to cracks in the HTL film caused by volume contractions, which inevitably results in significant VOC loss. These flaws prompted this research to develop a method involving hybrid organic ligand exchange using 3-mercaptopropionic acid (MPA) and 1,2-EDT (PbS-Hybrid) to overcome these drawbacks of VOC loss. The results indicated that the new exchange strategy improved the quality of the HTL film and benefited from the enhanced passivation of the quantum dot surface and better alignment of energy levels, and the average VOC of PbS-Hybrid devices is increased by approximately 25 mV compared to control devices. With the enhanced VOC, the average power conversion efficiency (PCE) of the devices is improved by 10%, with the highest PCE reaching 13.24%.

Flutter and divergence zones of perovskite solar cell-based panels of aircraft wings in subsonic airflow

Solar-powered aircraft have advantages such as quite long flight time and resource conservation. In recent years, with the improvements in solar cell efficiency, lightweight structural design, microelectronics, and automation control technology, more and more countries and organizations have conducted research on solar-powered aircraft. Solar cells are an important component of solar-powered aircraft systems. Perovskite solar cells have the advantages of high flexibility, lightweight, and high specific power, making them the ideal material for solar-powered aircraft wings. To receive as much sunlight radiation as possible and improve the lift-to-drag ratio of the entire aircraft, solar-powered aircraft have a high aspect ratio, making them more sensitive to changes in airflow. Therefore, the stability zones and vibration of perovskite solar cell (PSC) panels in subsonic airflow were studied for the first time. Additionally, to enhance the novelty of the paper and present more comprehensive results, the effect of the nanomaterial properties of one-layered perovskite solar cell substrates reinforced by carbon nanotubes and graphene platelets on the flutter and divergence phenomenon was investigated. To accurately simulate the displacement field after the composite perovskite panel is bent, Reddy's high-order shear deformation theory was adopted. The PSC panel's aerodynamic-elastic coupling motion equations were established by combining Hamilton's principle with the linear potential flow theory and the Bernoulli equation. The dynamic equations were discretized using a meshless numerical method to obtain the generalized multi-parameter characteristic equations. The obtained natural frequencies and critical divergence speeds were compared with published literature to validate the correctness of the aerodynamic model and laminated board model. The divergence instability and flutter instability of the PSC nanocomposite panel were investigated for changing the thickness, nano-fillers, porosity, laying angle, and aspect ratio of the substrate. We showed, that the PSC panel has a divergence instability state first, and then flutter instability appears. Additionally, the substrate nanomaterial parameters of the PSC panel significantly affect shifting divergence and flutter zones. Interestingly, the corresponding natural frequency increases when flutter occurs with an increase in the porosity volume.

Improving 3-Junction and 2-Junction solar cell efficiency by down-converting solar UV light to visible

The approach to efficiency improvement of space 3-Junction and 2-Junction solar cells, that involves a layer of down-converting material on the top of the cell, is presented. The layer consists of a polymer nanocomposite coating impregnated with the nanoparticles of inorganic compounds (fluorides or oxides) doped with rare earth ions down-converting solar UV light to visible matching the spectrum of the responsivity of the cell. Computational model of a solar cell is presented and used for processing the experimental data. Experimental results demonstrate an increase of the generated current and photoelectric efficiency.

Efficiency improvement of commercial silicon solar cells using bilayers of luminescent nanomaterials

Efficiency improvement of commercial silicon solar cells using bilayers of luminescent nanomaterials

(Invited) Plasma Processes on Metal Halide Perovskite Interfaces for Photovoltaic Applications

Metal Halide Perovskite (MHP) semiconductors are currently standing out for their exceptional optoelectronic properties and, particularly, for their exploitation in photovoltaics. Their structure can be described by the formula , where A is usually an organic cation, such as methylammonium (MA) or formamidinium (FA), B is a metal cation and X is a halogen anion, typically I or Br.The exceptional properties of MHPs derive by their hybrid organic-inorganic nature, which also allows for low-cost fabrication processing. The raise of perovskite photovoltaics 1 followed progresses on three main research fronts: i) material deposition optimization, ii) material compositional tuning and iii) device interface engineering. The interfaces play a fundamental role in the device function affecting charge extraction, recombination processes and material/device overall stability. Therefore, to further improve the performances of these devices, many surface processes have been applied to solar cells interfaces, most of which include a solution-based methodology 2. The aim of these treatments is not only to improve solar cells efficiency in terms of carrier concentration and transport properties, but also to improve the device stability under working conditions, which is one of the main issues of these materials.Among the different surface treatments exploitable, the use of plasma represents a solvent-free and non-invasive promising strategy to boost MHP solar cells performances. Plasma-deposited coatings on perovskite, as fluorocarbon polymers, have shown to improve material resistance to humidity and photoluminescence properties 3.We have explored the effect of low-pressure plasmas fed with different gases, namely Ar, , and , on Metylammonium Lead Iodide surface4. An interesting improvement of perovskite photoluminescence and solar cell efficiency was observed for Ar and plasma treatments, ascribable both to the removal of organic components, proven to be beneficial to device performances 5, and to other chemical and morphological modifications depending on the gas used. Starting from these results, new plasma surface treatments, plasma-assisted deposition and encapsulation processes will be object of study of future research, to achieve a more complete understanding of the interfacial defects and charge carrier dynamics and to further minimize performance losses and instability issues. References NREL Best Research-Cell Efficiency Chart. https://www.nrel.gov/pv/cell-efficiency.html Han TH, Tan S, Xue J, Meng L, Lee JW, Yang Y. Interface and Defect Engineering for Metal Halide Perovskite Optoelectronic Devices. Advanced Materials. 2019;31(47). doi:10.1002/adma.201803515 Armenise V, Colella S, Milella A, Palumbo F, Fracassi F, Listorti A. Plasma-Deposited Fluorocarbon Coatings on Methylammonium Lead Iodide Perovskite Films. Energies (Basel). 2022;15(13):4512. doi:10.3390/en15134512 Andrea Listorti, Sara Covella, Alberto Perrotta, et al. A study on plasma-assisted modifications of Methylammonium Lead Iodide Perovskite surfaces for photovoltaic applications. Xiao X, Bao C, Fang Y, et al. Argon Plasma Treatment to Tune Perovskite Surface Composition for High Efficiency Solar Cells and Fast Photodetectors. Advanced Materials. 2018;30(9):1-7. doi:10.1002/adma.201705176 Figure 1

Stability and efficiency improvement of TiO2-based dye-sensitized solar cells by surface modification of MgO

Stability and efficiency improvement of TiO2-based dye-sensitized solar cells by surface modification of MgO

Efficiency and stability improvement of non-fullerene organic solar cells with binary anode buffer layer

Efficiency and stability improvement of non-fullerene organic solar cells with binary anode buffer layer

Improvement of Solar Cell Efficiency and Electrical Energy of a Photovoltaic-Thermal System by Using Nanofluid

This communication presents the finite element method (FEM) analysis of the conjugate heat transfer across the PV/T panel. The PV/T system has several layers i.e., PV cell layer, thermal paste layer, reservoir wall and reservoir flow channel filled with nanofluid. The heat transfer equations for all layers have been constructed according to the conjugate heat transfer equation. The continuity, momentum and energy equations are solved numerically by using the FEM technique. The effects of various dimensionless parameters are discussed by plotting velocity, temperature, electrical output and thermal efficiencies. The result indicates that the average cell temperature keeps decreased by increasing nanoparticle concentration. The narrower flow channel has greater power output at the relatively low concentration while the wider flow channel has greater power output at the relatively high concentration. Thermal performance increases by 11% for every 10% increasing in nanoparticle volume fraction.

Latest Updates of Single-Junction Organic Solar Cells up to 20% Efficiency

Single-junction organic solar cells have reached a power conversion efficiency of 20% with narrow bandgap non-fullerene electron acceptor materials such as Y6, as well as with large band gap electron donor materials and their derivatives. The power conversion efficiency improvement of single-junction organic solar cells is a result of highly efficient light harvesting in the near-infrared light range and reduced energy losses with the most promising active layer layout currently available, Bulk-Heterojunction. Ternary blending is known to be the most advanced strategy to construct Bulk-Heterojunction structures in organic solar cells at present. In this review, we examine different devices based on Bulk-Heterojunction structures with efficient electron donors and acceptors. Then, we review the performance of binary and ternary organic solar cells with high power conversion efficiency, in conjunction with different anode and cathode interfaces used in recent studies of high-power conversion efficiency. Finally, we present perspectives on the future development of single-junction organic solar cells.

Tellurium Doping Inducing Defect Passivation for Highly Effective Antimony Selenide Thin Film Solar Cell

Antimony selenide (Sb2Se3) is emerging as a promising photovoltaic material owing to its excellent photoelectric property. However, the low carrier transport efficiency, and detrimental surface oxidation of the Sb2Se3 thin film greatly influenced the further improvement of the device efficiency. In this study, the introduction of tellurium (Te) can induce the benign growth orientation and the desirable Sb/Se atomic ratio in the Te-Sb2Se3 thin film. Under various characterizations, it found that the Te-doping tended to form Sb2Te3-doped Sb2Se3, instead of alloy-type Sb2(Se,Te)3. After Te doping, the mitigation of surface oxidation has been confirmed by the Raman spectra. High-quality Te-Sb2Se3 thin films with preferred [hk1] orientation, large grain size, and low defect density can be successfully prepared. Consequently, a 7.61% efficiency Sb2Se3 solar cell has been achieved with a VOC of 474 mV, a JSC of 25.88 mA/cm2, and an FF of 64.09%. This work can provide an effective strategy for optimizing the physical properties of the Sb2Se3 absorber, and therefore the further efficiency improvement of the Sb2Se3 solar cells.

Photovoltaics literature survey (no. 182)

Photovoltaics literature survey (no. 182)

Theoretical simulation and experimental perspective of refractive index-controlled silicon nanofilms for solar cell efficiency improvement

Theoretical simulation and experimental perspective of refractive index-controlled silicon nanofilms for solar cell efficiency improvement

Efficiency Improvement of Industrial Silicon Solar Cells by the POCl3 Diffusion Process

To improve the efficiency of polycrystalline silicon solar cells, process optimization is a key technology in the photovoltaic industry. Despite the efficiency of this technique to be reproducible, economic, and simple, it presents a major inconvenience to have a heavily doped region near the surface which induces a high minority carrier recombination. To limit this effect, an optimization of diffused phosphorous profiles is required. A "low-high-low" temperature step of the POCl3 diffusion process was developed to improve the efficiency of industrial-type polycrystalline silicon solar cells. The low surface concentration of phosphorus doping of 4.54 × 1020 atoms/cm3 and junction depth of 0.31 μm at a dopant concentration of N = 1017 atoms/cm3 were obtained. The open-circuit voltage and fill factor of solar cells increased up to 1 mV and 0.30%, compared with the online low-temperature diffusion process, respectively. The efficiency of solar cells and the power of PV cells were increased by 0.1% and 1 W, respectively. This POCl3 diffusion process effectively improved the overall efficiency of industrial-type polycrystalline silicon solar cells in this solar field.