Fabrication Of Cells Research Articles

Progress on critical cell fabrication parameters and designs for advanced lithium-sulfur batteries.

Since 1990, commercial lithium-ion batteries have made significant strides, approaching their theoretical performance limits, albeit with escalating costs. To address these challenges, attention has shifted toward lithium-sulfur batteries, which offer higher theoretical energy densities and cost-effectiveness. However, lithium-sulfur cells face challenges such as active-material loss, excessive electrolyte usage, and rapid degradation of lithium-metal anodes. To overcome these issues, research has focused on optimizing cell configurations and fabrication parameters while exploring novel electrolytes and electrode materials. This feature article delves into the intrinsic material challenges and extrinsic engineering issues in current lithium-sulfur research and explores the development of advanced lithium-sulfur cells with crucial progress on high-loading sulfur cathodes, lean-electrolyte cells, and solid-state electrolytes. Moreover, it outlines the fundamental principles, structures, performances, and developmental trajectories indicated in research articles published after 2020, highlighting future research directions aimed at resolving key challenges for the practical application of lithium-sulfur cells.

Enhancing perovskite solar cell performance through PbI2 in situ passivation using a one-step process: experimental insights and simulations.

The in situ passivation of a methylammonium lead triiodide (MAPbI3) phase spin-coated via a one-step process was experimentally investigated to elucidate their fundamental properties. Structural analysis revealed that MAPbI3 adopts a tetragonal crystal structure with a small excess of PbI2 (0.03 M) segregating at grain boundaries. Optical characterization indicated a band gap of 1.53 eV, highlighting the material's potential as an effective visible light absorber. To facilitate the fabrication of efficient perovskite solar cells (PSCs), we employed a primary n-i-p planar structure (ITO/SnO2/MAPbI3/spiro-OMeTAD/Au) in drift-diffusion SCAPS-1D simulations using experimental data from MAPbI3 layers containing excess PbI2. The simulations predicted a high power conversion efficiency (PCE) of approximately 24%. We further analyzed the impact of series resistance, shunt resistance, MAPbI3 thickness, defect density, as well as radiative and Auger recombination on photovoltaic performance, aiming to identify optimal parameters for enhanced device efficiency. Additionally, the use of ohmic contacts with AZO and IZO as the front and rear contacts, respectively, in the optimized device structure (AZO/SnO2/MAPbI3/spiro-OMeTAD/IZO) resulted in a PCE of 26.03%. These findings provide valuable insights for future research aimed at achieving high-efficiency bifacial MAPbI3 perovskite solar cells.

Recent trends on the application of phytochemical-based compounds as additives in the fabrication of perovskite solar cells

Phytochemical-based additives have functional groups that can modulate the nucleation and crystallization process of perovskite films resulting in improved optoelectronic and degradation resistance.

An ambient process for hole transport layer-free highly stable MAPbI3 by addition of MACl for efficient perovskite solar cells

An ambient process for the fabrication of HTL-free carbon-based perovskite solar cells at room temperature with the addition of an optimized amount of MACl into the perovskite precursor solution.

DLTS analysis of interface and near-interface bulk defects induced by TCO-plasma deposition in carrier-selective contact solar cells

We investigate the electrical characteristics of defects at the SiO2/Si interface, within the adjacent Si crystal, and through the depth profile of the bulk defect using three-dimensional deep-level transient spectroscopy (3D-DLTS). These defects are introduced by the reactive plasma deposition technique employed for depositing transparent conductive oxides in the fabrication of carrier-selective contact-type solar cells. To control the surface potential near the Si surface, we apply a varying voltage to obtain DLTS signals as functions of both temperature and Fermi level at the SiO2/Si interface. Using machine learning for 3D-DLTS spectral analysis, we estimate the capture cross sections, energy levels, densities, and depth profiles of these process-induced defects. The experimental results indicate the existence of three types of electron traps within the bulk defects, ranging from the interface to a depth of ∼70 nm. The electrical properties of these bulk defects suggest the presence of oxygen-related defects within Si. On the other hand, regarding the properties of interface defects, the capture cross sections and the defect densities are estimated as a function of their energy levels. They suggest that the defects at the SiO2/Si interface are likely oxygen-related PL centers.

Solution-based electrical doping of organic photovoltaics with non-fullerene acceptors facilitated by solvent vapor pre-treatment

Solution-based electrical doping of organic semiconductors using 12-molybdophosphoric acid (PMA) hydrate has been shown to allow p-type doping of conjugated polymers over a limited depth from the surface, enabling the fabrication of organic solar cells with a simplified device architecture. However, the doping level of certain conjugated polymers using PMA was found to be limited by the polymer film volume. Here, we report a modified PMA doping technique based on film volume expansion that is applicable to device fabrication, leading to hole-collecting layer-free non-fullerene organic photovoltaic devices, which exhibit a comparable photovoltaic performance to those with a commonly evaporated MoO3 hole-collecting layer.

Fabrication of high-performance flexible perovskite solar cells based on synergistic passivation strategy

Flexible perovskite solar cells have attracted much attention in the scientific community due to their lightweight nature, high flexibility, and superior power-to-mass ratio. One of the most effective strategies for enhancing the power conversion efficiency of these cells involves addressing grain boundary defects within the perovskite films and interfacial defects between the perovskite films and charge transport layers. In this work, we optimize the performance of inverted flexible perovskite solar cell by using octadecylamine hydrochloride (OACl) as both an additive and a surface passivating agent to achieve synergistic passivation to the bulk phase and surface. The incorporation of OACl in the perovskite precursor solution results in the enlarging of the perovskite crystal grains, enhancing crystallinity, and passivating of grain boundary defects within the perovskite film. This optimization leads the open-circuit voltage to increase from 1.07 to 1.12 V, fill factor from 70.86% to 75.04%, and power conversion efficiency from 18.08% to 20.12%. In addition, the OACl solution is used to passivate the surface of perovskite film, resulting in a smoother perovskite surface, fill the grain boundaries, and reduce the defect density on the perovskite surface. As a result, the optimized device exhibits an open-circuit voltage of 1.15 V, fill factor of 76.15%, and ultimately achieves a power conversion efficiency of 20.80% for flexible perovskite solar cells. The synergistic passivation strategy based on OACl used in this work provides an effective approach for fabricating efficient flexible perovskite solar cells.

Research progress of green antisolvent for perovskite solar cells.

Conventional antisolvents such as chlorobenzene and benzotrifluoride are highly toxic and volatile, and therefore not preferred for large-scale fabrication. As such, green antisolvents are favored for the eco-friendly fabrication of perovskite films. This review primarily discusses the impact of various green antisolvents on the fabrication of thin perovskite films and analyzes the main chemical characteristics of these green antisolvents. It also interprets the impact of green antisolvent treatment on crystal growth and nucleation crystallization mechanisms. It introduces the effective fabrication of large-area devices using green antisolvents and analyzes the mechanisms by which green antisolvents enhance device stability. Subsequently, several green antisolvents capable of preparing highly stable and efficient devices are listed. Finally, we outline the key challenges and future prospects of antisolvent treatment. This review paves the way for green fabrication of industrial perovskite solar cells.

Fabrication of Double Antireflection Layer of SiO2/SiNx via Spin Coating and Brush Painting for Enhanced Performance of Silicon Solar Cells

This research investigates the optical, structural, and photovoltaic attributes of a dual antireflection (AR) layer deposition on crystalline silicon (c–Si) solar cells using second SiO2 layer on SiNx AR. The second SiO2 AR layer on a SiNx AR-based c–Si solar cell was fabricated utilizing both spin coating and brush painting techniques, resulting in a unique double (SiO2/SiNx) AR layer. The initial SiNx AR layer was deposited on the c–Si solar cell through plasma-enhanced chemical vapor deposition (PECVD), while the SiO2 layer was subsequently applied using two different methods such as spin coating at 5000 rpm for 20 s and brush painting, separately, on Si solar cell. The double (SiO2/SiNx) AR layer on the Si wafer exhibited a substantial reduction in average reflectance, approximately 6.02% through spin coating and 5.17% through brush painting, within the wavelength range of 400–1000 nm when compared to a textured silicon wafer. The fabricated solar cell featuring the double (SiO2/SiNx) AR layer, achieved a power conversion efficiency of 15.21% and 17.57% for spin coating and brush painting, respectively. The utilization of the double (SiO2/SiNx) AR layer through brush painting on the Si solar cell not only provided low reflectance but also demonstrated excellent surface properties, making it a promising candidate for the cost-effective fabrication of high-performance Si solar cells.

3D printed electrolyte-supported solid oxide cells based on Ytterbium-doped scandia-stabilized zirconia

Solid oxide cells (SOC) are an efficient and cost-effective energy conversion technology able to operate reversibly in fuel cell and electrolysis mode. Electrolyte-supported SOC have been recently fabricated employing 3D printing to generate unique geometries with never-explored capabilities. However, the use of the state-of-the-art electrolyte based on yttria-stabilized zirconia limits the current performance of such printed devices due to a limited oxide-ion conductivity. In the last years, alternative electrolytes such as scandia-stabilized zirconia (ScSZ) became more popular to increase the performance of electrolyte-supported cells. In this work, stereolithography 3D printing of Ytterbium-doped ScSZ was developed to fabricate SOC with planar and corrugated architectures. Symmetrical and full cells with about 250 μm- thick electrolytes were fabricated and electrochemically characterized using impedance spectroscopy and galvanostatic studies. Maximum power density of 500 mW cm−2 in fuel cell mode and an injected current of 1 A cm−2 at 1.3 V in electrolysis mode, both measured at 900 °C, were obtained demonstrating the feasibility of 3D printing for the fabrication of high-performance electrolyte-supported SOC. This, together with excellent stability proved for more than 350 h of operation, opens a new scenario for using complex-shaped SOC in real applications.

DSSC Fundamentals and Optimization Materials :A Review

Recently, researchers are focusing on renewable energy sources such as wind energy, Hydro-thermal energy, and solar energy. In this research article DSSC fundamentals and optimized materials are discussed and compared. The maximum efficiency reported by the researcher is 12% using Ru (II) dyes. The efficiency of DSSC depends on the various factors such as working electrode material, counter electrode material, dye used in preparation of solar cell are discussed. The simplest technique used for fabrication of DSSC solar cell is doctor blade method also discussed in this review article.

Water-based layer-by-layer processing enables 19% efficient binary organic solar cells with minimized thickness sensitivity

A mesoporous layer was constructed by a donor-based nanoparticulate water-ink, which facilitates the infiltration of the acceptor, allowing the fabrication of efficient organic solar cells with a high thickness tolerance.

Construction of tumor organoids and their application to cancer research and therapy.

Cancer remains a severe public health burden worldwide. One of the challenges hampering effective cancer therapy is that the existing cancer models hardly recapitulate the tumor microenvironment of human patients. Over the past decade, tumor organoids have emerged as an in vitro 3D tumor model to mimic the pathophysiological characteristics of parental tumors. Various techniques have been developed to construct tumor organoids, such as matrix-based methods, hanging drop, spinner or rotating flask, nonadhesive surface, organ-on-a-chip, 3D bioprinting, and genetic engineering. This review elaborated on cell components and fabrication methods for establishing tumor organoid models. Furthermore, we discussed the application of tumor organoids to cancer modeling, basic cancer research, and anticancer therapy. Finally, we discussed current limitations and future directions in employing tumor organoids for more extensive applications.

Preparation of high-performance large-area perovskite solar cells by atomic layer deposition of metal oxide buffer layer

Perovskite solar cells have been widely recognized as the most promising new-type photovoltaic device due to its power conversion efficiency rapidly increasing from 3.8% to over 26% in merely fifteen years. However, the high performances are achieved mainly on small area cells with an active area lower than 0.1 cm<sup>2</sup>. When enlarging the active area of perovskite solar cells, the efficiency falls dramatically. So, how to reduce the gap between performances of small area cells and large area cells gradually becomes a critical point in the path towards the commercialization of perovskite photovoltaic technology. Herein, a strategy of pre-growing thin layer of TiO<sub>2</sub> on a rough FTO substrate by atomic layer deposition method before spin-coating SnO<sub>2</sub> nanoparticles is proposed. Due to the inherent conformal film growth mode of atomic layer deposition, the FTO substrate can be completely covered by TiO<sub>2</sub>, thus preventing the direct contact between local protrusions of FTO and perovskite layer and impeding the current leakage phenomenon, which can be verified by the measurements from X-ray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy, and further proved by the dark current measurement. By using this method, the repeatability and consistency of the small area cell fabrication technology on the same substrate are improved obviously. The improved electron transport process revealed by photoluminescence results and incident light management process revealed by external quantum efficiency results also brings about better solar cell performances. More importantly, highly efficient 0.5 cm<sup>2</sup> large area perovskite solar cells are fabricated through optimization of TiO<sub>2</sub> thickness. When growing 200 cycles TiO<sub>2</sub> (~9 nm in thickness) by using atomic layer deposition technology, the champion large area perovskite solar cell possesses a power conversion efficiency as high as 24.8% (certified 24.65%). The device performances also show excellent repeatability between different fabrication batches. The perovskite solar cell with TiO<sub>2</sub> buffer layer grown by the atomic layer deposition method can still retain over 95% of its initial efficiency after having been stored in a nitrogen atmosphere for 1500 h. The technique proposed in this paper can be helpful in manufacturing perovskite solar cell modules in the realistic photovoltaic market and can be extended to the large area fabrication of other perovskite optoelectronic devices such as light emitting diode, laser and detector.

Efficient monodisperse upconversion composite prepared using high-density local field and its dual-mode temperature sensing.

Enhanced upconversion via plasmonics has considerable potential in biosensors and solar cells; however, conventional plasmonic configurations such as core-shell assemblies or nanoarray platforms still suffer from the compromise between the enhancement factor and monodispersity, which has failed to meet the requirement of the materials for the in vivo all-solution-prepared solar cells and biosensors. We herein report a monodisperse metal-dielectric-metal (MDM) type upconverted hybrid material with high efficiency. The lanthanide-doped upconversion nanoparticles (UCNPs) were sandwiched by two gold nanodisk mirrors, and the highly localized excitation field around the UCNPs together with the efficient coupling enhanced the upconversion. The upconversion intensity can then be effectively regulated and improved by three to four orders of magnitude. As per the measurement of the temperature-dependent fluorescence intensity and spectra shift, a dual-mode nanothermometer based on our proposed hybrid materials was demonstrated. This MDM-type upconverted hybrid material demonstrated the merits of high efficiency and monodispersity, which demonstrated promise in in vivo biosensors and solar cell fabrication techniques such as spin-coating and roll-to-roll.

Wet chemical poly-Si(n) wrap-around removal for TOPCon solar cells

This work gives an overview on different technological solutions for polysilicon removal in industrial tunnel oxide passivated contact (i-TOPCon) n-type silicon solar cell fabrication. The removal of parasitically deposited poly-Si layers on the front and the edges is a mandatory requirement for a low reverse bias junction leakage current (Irev). A polysilicon removal study on wafer level shows (i) that the efficient removal of the surface oxide layer before poly-Si etching is crucial to achieve short etching times and (ii) that an additive in the KOH solution enhances etching selectivity between poly-Si and silicon oxide surfaces. To evaluate the impact on device level, TOPCon cells have been fabricated in parallel using in-situ n-doped PECVD and LPCVD layers, as well as ex-situ LPCVD poly-Si layers, with another variation of poly-Si removal processes, namely wet chemical inline, wet chemical batch cluster and atmospheric dry etching (ADE). Our results show that a two-minute inline polysilicon removal in hot KOH meets the Irev qualification in case of as deposited in-situ doped layers, whereas for ex-situ doped layers a batch process with a five-minute KOH etching time is needed. LPCVD poly-Si cells show efficiencies above 23%, PECVD poly-Si cells with a batch cluster poly-Si removal process up to 23.4%.

Exploring the interplay of the water–methanol solvent admixture on the optoelectronic properties of spray pyrolyzed fluorine-doped tin oxide thin films and their potential use in solar cell fabrication

A FTO thin film, M90, prepared using 90 vol% CH3OH, exhibits the highest FOM, indicating its potential use in photovoltaics and other applications.

THE OPTIMIZATION OF P3HT:PCBM THIN FILM THICKNESS FOR ORGANIC SOLAR CELLS

This study presents the complex relationship between film thickness and the properties of P3HT:PCBM thin films, looking at how different thicknesses affected their structural and optical properties. Poly(3, hexylthiophene) (P3HT) and poly(3, hexylthiophene) (PCMB) were blended in a 0.6:1 ratio and deposited using spin coating techniques. The research involve investigating the resulting changes in surface topography, optical properties, and electrical behaviour by systematically adjusting the film thickness through multiple coating repetitions ranging from one to three repetitions. Profilometric analysis revealed a direct relationship between film thickness and surface roughness, highlighting the importance of thickness in interfacial interactions within solar cells. Optical studies revealed fascinating trends in absorbance, transmittance, absorption coefficient, and extinction coefficient, highlighting the films' behaviour at various wavelengths. Surprisingly, regardless of thickness, the optical band gap remained constant, providing valuable insights for optimizing photon energy conversion. Measurements of the Hall effect revealed the effect of thickness on carrier mobility, concentration, conductivity, resistivity, and Hall voltage. Thinner films had higher mobility but lower carrier concentration, revealing a delicate balance critical for optimizing charge transport. The comprehensive analysis of the study sheds light on the complex interplay between film thickness and various properties, providing useful guidance for designing efficient P3HT:PCBM organic solar cells. This study's findings highlight the importance of precise control over film dimensions in improving the performance and efficiency of organic photovoltaic devices. This investigation paves the way for tailored approaches in the fabrication of next-generation organic solar cells, pushing the limits of renewable energy technology.

Green Solvent Accelerates Spiro‐OMeTAD Oxidation for Efficient Perovskite Solar Cells

As one of the most widely used hole transport materials (HTMs) in optoelectronics devices, 2,2’,7,7’‐tetrakis[N,N‐di(4‐methoxyphenyl)amino]‐9,9‐spirobifluorene (spiro‐OMeTAD) has endowed perovskite solar cells (PSCs) with record power conversion efficiencies (PCEs). However, the long oxidation time in the ambient atmosphere is time‐consuming. Furthermore, commonly used solvents for spiro‐OMeTAD film processing such as chlorobenzene (CB) are toxic, which severely hinders the commercialization of PSCs. Herein, ethyl acetate (EA) serves as a superior green solvent alternative to the typical processing solvent, which substantially reduces the oxidation time of spiro‐OMeTAD. Without postoxidation treatment and any other additional oxidizing agents, the resultant device delivers a high PCE of 23.3%, significantly outperforming the CB‐based device. It is also the highest efficiency obtained from nonhalogenated solvent‐processed spiro‐OMeTAD. The electrostatic potential mapping demonstrates that the electron density at nitrogen atoms of EA‐processed spiro‐OMeTAD is more delocalized, leading to a faster oxidation. Furthermore, the processing solvent EA is a green solvent with low toxicity, and the amount of HTMs used in the fabrication of solar cells can be dramatically reduced. This study provides a new solution for processing spiro‐OMeTAD, which is ideal for the mass production of PSCs.

Flexible Perovskite Solar Cells on Ultra‐Thin Stainless‐Steel with a Power‐to‐Weight Ratio over 3000 W kg−1

Ultra‐thin stainless‐steel substrates with excellent water‐oxygen barrier properties and high thermal and electrical conductivities are suitable for the fabrication of lightweight and flexible perovskite solar cells (FPSCs). However, the deposition of dense perovskite films on stainless steel by the solution method is crucial because short circuits caused by perovskite holes are fatal to parallel structures. Herein, a single crystal (SC) is incorporated into the precursor solution to reduce the formation of holes in perovskite films on smooth stainless‐steel substrates. Additionally, a magnetic method is developed based on the properties of stainless steel to fix and fabricate FPSCs nondestructively on ultra‐thin stainless‐steel films with a thickness as low as 5 μm. Furthermore, 4,6‐dimethyl‐2‐mercaptopyrimidine (DMI) was introduced to passivate the surface of the perovskite film, optimizing the contact properties of the perovskite heterojunction and adjusting the energy level of the perovskite/C60 interface. Finally, ultra‐thin FPSCs achieved a champion power conversion efficiency (PCE) of 20.24% on an active area of 1.012 cm2 and a power‐to‐weight ratio over 3000 W kg−1. Moreover, under continuous illumination, the stainless‐steel substrates exhibited better photothermal stability than the polymer substrates. This method provides a basis for the fabrication of lightweight, low‐cost, and large‐area FPSCs.