Solar Cell Applications Research Articles

An extensive investigation of structural, electronic, and optical properties of inorganic perovskite Ca3AsCl3 for photovoltaic and optoelectronic applications: A first-principles approach using Quantum ATK tool

Perovskite-based solar cells have been researched for quite some time with the highest reported values of power conversion efficiencies at around 30.9 %. However, commonly investigated materials like lead halide perovskites, mixed halide perovskites, and tin-based perovskites have challenged researchers in terms of stability, toxicity, scalability, etc. In an attempt to overcome these limitations, we have conducted in-depth studies on perovskite material, i.e. Ca3AsCl3 using the QuantumATK Tool to establish its adaptability to solar cell applications. This material's mechanical stability has been established using the Born-Huang criteria. While analyzing electronic properties, Ca3AsCl3 possessed a direct energy bandgap of 1.742 eV. At 3.2 eV, the dielectric constant values, susceptibility, optical conductivity, and polarizability are reported to be 5.06, 4.06, 1.748 × 103 AV−1cm−1, and 6.859 × 10−39 C m2V−1 respectively. Current density values calculated using the FE model for the Ca3AsCl3-based perovskite Solar Cell (PSC) designed through the LCAO Device calculator, are in excellent agreement with those obtained from the SCAPS 1D model. The obtained values of the mechanical, electrical, optical, and structural properties of Ca3AsCl3 suggest promising applications in solar cells, optoelectronic devices, and a wide range of flexible electronic devices.

High-Pressure oC16-YBr3 Polymorph Recoverable to Ambient Conditions: From 3D Framework to Layered Material.

Exfoliation of graphite and the discovery of the unique properties of graphene─graphite's single layer─have raised significant attention to layered compounds as potential precursors to 2D materials with applications in optoelectronics, spintronics, sensors, and solar cells. In this work, a new orthorhombic polymorph of yttrium bromide, oC16-YBr3 was synthesized from yttrium and CBr4 in a laser-heated diamond anvil cell at 45 GPa and 3000 K. The structure of oC16-YBr3 was solved and refined using in situ synchrotron single-crystal X-ray diffraction. At high pressure, it can be described as a 3D framework of YBr9 polyhedra, but upon decompression below 15 GPa, the structure motif changes to layered, with layers comprising edge-sharing YBr8 polyhedra weakly bonded by van der Waals interactions. The layered oC16-YBr3 material can be recovered to ambient conditions, and according to Perdew-Burke-Ernzerhof-density functional theory calculations, it exhibits semiconductor properties with a band gap that is highly sensitive to pressure. This polymorph possesses a low exfoliation energy of 0.30 J/m2. Our results expand the list of layered trivalent rare-earth metal halides and provide insights into how high pressure alters their structural motifs and physical properties.

Theoretical Design of Tellurium-Based Two-Dimensional Perovskite Photovoltaic Materials.

In recent years, the photoelectric conversion efficiency of three-dimensional (3D) perovskites has seen significant improvements. However, the commercial application of 3D perovskites is hindered by stability issues and the toxicity of lead. Two-dimensional (2D) perovskites exhibit good stability but suffer from low efficiency. Designing efficient and stable lead-free 2D perovskite materials remains a crucial unsolved scientific challenge. This study, through structural prediction combined with first-principles calculations, successfully predicts a 2D perovskite, CsTeI5. Theoretical calculations indicate that this compound possesses excellent stability and a theoretical efficiency of up to 29.3%, showing promise for successful application in thin-film solar cells. This research provides a new perspective for the design of efficient and stable lead-free 2D perovskites.

Numerical study of mid-infrared broadband perfect absorber based on dielectric/aluminium doped zinc oxide multilayer films

We propose a lithography-free wide-angle polarization-insensitive ultra-broadband absorber by using multilayer films consist of five pairs of aluminium doped zinc oxide (AZO) and a dielectric film which is supposed to be fabricated on glass substrate. The absorption spectrum of the proposed model is calculated by using transfer matrix method.The analytic results show that the absorptivity is larger than 95% with normal incidence light in the wavelength range from 7.5μm to 20μm and having high transmittance at the visible wavelength range from 0.4μm to 0.8μm range. Further, the effect of incident angle and polarization on the absorption spectrum are also investigated. The absorption spectrum of the proposed design is highly tunable on changing the damping constant of the AZO film. The electric field and magnetic distributions at different wavelengths show that the absorption is mainly originated due to the constructive interference of electromagnetic waves in the multilayer films. Such physical mechanism of broadening bandwidth based on increasing the carrier concentration of the highly visible transparent conducting films have pave a new direction for the design of tunable broadband absorber in different frequency band. Meanwhile, this broadband absorber is a good candidate for the potential applications in daytime radiation cooling system in the mid-infrared frequency band and also used as transparent conducting electrode in solar cell applications.

Performance optimization of ETL-free bifacial perovskite solar cells for flexible devices: A simulation study

The versatile applications of flexible perovskite solar cells (PSCs) have made them promising energy-harvesting devices in our daily lives. The electron transport layer (ETL)-free PSCs offer a flexible approach for harnessing energy while adding a bifacial approach that can further improve the device performance. In our study, we have optimized ETL-free bifacial PSCs via simulation by selecting the suitable front transparent electrode (FTE), hole transport layer (HTL), and rear transparent electrode (RTE). Our investigation reveals that a potential well-like structure, associated with a small conduction band offset (CBO) at the FTE/perovskite interface holds significant potential for enhancing the power conversion efficiency (PCE) of the device. The upward shift in the valance band of HTL promotes recombination and reduces the device performance. The bandgap and electron affinity of RTE highly influence the band alignment at HTL/RTE interface. The NiO/Ag/NiO (NAN) tri-layer RTE provides a better band alignment with HTL, and improves the charge transportation and, hence, the device performance. Moreover, the thickness of the interfacial defect layer at the FTE/perovskite and perovskite/HTL interfaces significantly impacts device performance. In optimizing the perovskite absorber layer, a perovskite bandgap of 1.4 eV shows maximum device performance. Our optimized device shows a remarkable PCE of >27% for both front and rear illumination.

TiO2 nanoparticle seeds transformed into nanotubes for effective dye-sensitized solar cell application

Morphology plays a vital role in dye-sensitized solar cells (DSSCs) due to their high surface area, dye adsorption and electron transport. In this study, we have designed and fabricated titanate nanotube photoanodes by a simple one-step hydrothermal method. High-resolution transmission electron microscope (HRTEM) analysis revealed the transformation of nanoparticles to nanotube morphology. Brauner-Emmett-Teller (BET) method showed the enhanced surface area and pore diameter of nanotubes. TiO2 nanotube photoanode showed excellent energy conversion efficiency (2.38 %), short circuit current densities (Isc) (6.29 mA/cm2), and fill factors (FF) (0.63), respectively.

Two-step preparation of methylammonium lead triiodide perovskite film via electrospray deposition of methylammonium iodide solution for solar cell applications

Solution-processable perovskite solar cells (PSCs) have the potential to revolutionize solar cell technology by enabling low power generation costs via low-cost device fabrication. However, most existing research regarding PSCs relies on the spin-coating method, which is not conducive to large-area film deposition. Therefore, the development of an alternative deposition method for perovskite films has become increasingly important for commercialization, for which electrospray deposition is a promising technique. This study investigates the two-step preparation of methylammonium lead triiodide (MAPbI3) perovskite films via the electrospray deposition of a methylammonium iodide (MAI) solution on a spin-coated PbI2 film. The gradual conversion of PbI2 to MAPbI3 with increasing MAI deposition time was revealed, accompanied by an increase in the size of the perovskite crystals. In addition, PSCs were successfully fabricated by electrospraying MAI, achieving a considerable power conversion efficiency of 7.86 % at the optimal MAI deposition time.

Insight into the structural, electronic, mechanical, and optical properties of Pb-free new inorganic perovskite Mg3SbX3 (X = I, Br, Cl, F) via first-principles analysis

The structural, electronic, mechanical, and optical properties of lead-free new inorganic halide perovskites of Mg3SbX3 (X = I, Br, Cl, F) have been investigated in detail using DFT calculations in this work. Here, all the compounds exhibit cubic phases with the space group Pm-3m (221). Upon detailed analysis, the Mg3SbI3, Mg3SbBr3, Mg3SbCl3, and Mg3SbF3 perovskites have shown semiconducting behavior with direct band gaps of 0.186 eV, 1.097 eV, 1.655 eV, and 3.460 eV, respectively, making them suitable for solar cell applications. Furthermore, elasticity constants reveal that all four perovskites are brittle, stiff, strong, and mechanically stable. According to optical data examined, there is significant absorption and low losses between 2 eV to 10 eV which is very useful for solar cells and optoelectronic devices.

A combined experimental and simulation study of multiphase bimetallic iodides semiconductor solar cell

The need of high quantum efficiency and stable semiconductor for the photovoltaics are always highly required. In this work, four phase containing multiphase bimetallic iodide (MPBI) compound was synthesized at room temperature by simple and novel chemical route. Synthesized compound was studied for structural, optical, and morphologic properties. The compound structural and phase confirmation was done by XRD, FT-IR, Raman spectroscopy and TEM studies. Optical properties such as absorption and emission characteristics were studied by UV-Visible spectroscopy and fluorescent spectroscopy respectively. The surface morphology and the elemental composition mapping was carried out using SEM and TEM methods. The detailed characterization inferred that high-temperature stable phase Ag4PbI6 was stabilized at room temperature along with AgI, PbI2 and Ag. From the obtained results, the mechanism of Ag4PbI6 phase formation is proposed and discussed. The synthesized semiconductor compound was studied for solar cell applications and obtained efficiency is 5.14 %. Further, the experimental solar cell results were verified using simulation results. This is one of the very few works which reports on room temperature stabilized high temperature stable Ag4PbI6 phase containing multiphase compound.

Effect of nickel oxide concentration on titanium oxide bilayer photoanode for dye-sensitized solar cell application

The mesoporous titanium oxide has attracted significant attention as a photoanode material for Dye-Sensitized Solar Cells (DSSCs). In the present work, we coated a planar NiO layer on the TiO2 film to minimize charge recombination with the dye and/or electrolyte molecules. The structural, morphological, elemental, optical, and electrical properties of the TiO2 and bi-layered TiO2/NiO films were studied using various characterization techniques. DSSCs based on N3 dye-sensitized TiO2 and bi-layered TiO2/NiO films were fabricated using PI as the redox electrolyte. The photocurrent density–voltage (J–V) characteristics of the DSSCs were studied using a solar simulator. Various parameters, such as open-circuit voltage (Voc), short-circuit photocurrent density (Jsc), and fill factor (FF), were calculated from the J–V characteristics. DSSCs based on bi-layered TiO2/NiO films showed superior performance compared to bare TiO2 films. The J–V characteristics of bilayer film shows enhanced open-circuit voltage (Voc) ~ 0.56 V, short-circuit current density (Jsc) ~ 2.14 mA/cm2, fill factor (FF) ~ 75%, and efficiency (ƞ) ~ 0.91%. The TiO2/NiO solar cell showed a ~ 28% increase in efficiency compared to TiO2-based DSSC. Hence, the bi-layered TiO2/NiO films have potential applications in optoelectronic and photovoltaic devices.

Elucidating the Effects of Cr-S Variations in Cr-Doped CZTS for Intermediate Band Solar Cell Applications

Intermediate band (IB) materials, such as chromium-doped Cu2ZnSnS4 (CZTS:Cr) show promise for surpassing the Shockley-Queisser limit in solar cells. This study explores the effects of sulphur variation in this film. Sulphurization results in a layered structure, with Cr-poor micron-sized grains on top and Cr-rich nanograins at the bottom preventing complete crystallization. Optimization improves the Cu2ZnSnS4 (CZTS) crystallization and introduces additional absorption peaks at 1.15 eV and 1.31 eV, alongside the fundamental 1.55 eV absorption using 47.1 mg of sulphur content. CZTS:Cr device fabricated achieve a threefold increase in current density (Jsc) compared to undoped samples. These findings are crucial for advancing intermediate band solar cell (IBSC) based on CZTS:Cr IB material.

Novel Ternary Halide Perovskites - CaKI3 and CaRbI3 : Investigation of structural, electronic and optical properties for optoelectronic applications.

The full-potential linearized augmented plane wave approach is used in this work to investigate the structural, electronic, elastic, thermal, and optical properties of CaKI3 and CaRbI3 cubic perovskite compounds using GGA_PBE and TB_mBJ approximations. The structures have been relaxed and ground state structural parameters are calculated. Density of states calculated reveal narrow band gaps which are around Schockley-Queisser limit(Eg≈1.34 eV). Optical characteristics imply that CaKI3 may be more appropriate for solar cell applications than CaRbI3.

Elucidating the effects of Cr–S variations in Cr-doped CZTS for intermediate band solar cell applications

Intermediate band (IB) materials, such as chromium-doped Cu2ZnSnS4 (CZTS:Cr) show promise for surpassing the Shockley-Queisser limit in solar cells. This study explores the effects of sulphur variation in this film. Sulphurization results in a layered structure, with Cr-poor micron-sized grains on top and Cr-rich nanograins at the bottom preventing complete crystallization. Optimization improves the Cu2ZnSnS4 (CZTS) crystallization and introduces additional absorption peaks at 1.15 eV and 1.31 eV, alongside the fundamental 1.55 eV absorption using 47.1 mg of sulphur content. CZTS:Cr device fabricated achieve a threefold increase in current density (Jsc) compared to undoped samples. These findings are crucial for advancing intermediate band solar cell (IBSC) based on CZTS:Cr IB material.

Growth and optimization of spray coated Cu2BaSnS4 thin films for solar photovoltaic application

Quaternary multicomponent Cu2BaSnS4 (CBTS) has emerged as a potential absorber material due to its abundant and nontoxic constituents, high absorption coefficient (10−4 cm−1) and suitable bandgap (1.5–2.0 eV) for the solar photovoltaic application. In this study, polycrystalline CBTS thin layers have been deposited by a typical spray pyrolysis technique on glass substrates using different substrate temperatures (Ts = 200, 250, 300 and 350 °C) followed by annealing in a sulfur-rich atmosphere at 550 °C under an argon flow. The (micro-)structural, compositional, and optical properties of both types of films have been studied. Analysis of x-ray diffractogram (XRD) patterns for all acquired films showed the presence of polycrystalline CBTS alongside various secondary phases, including Cu2SnS3 being predominant. Nonetheless, the XRD of the films deposited at 250 °C and annealed at 550 °C showed only the CBTS phase. Raman spectroscopy confirm the formation of the trigonal phase of CBTS. The presence of Cu, Ba, Sn and S in CBTS thin films was confirmed by X-ray photoelectron spectroscopy and Energy-dispersive X-ray spectroscopy. Scanning electron micrographs show a smooth and dense structure with enhanced crystallinity and improved uniformity. Overall, the physical properties of CBTS thin films were found to be spray deposition temperature dependent. An appropriate optical band gap of 1.6 to 1.8 eV and a compact structure indicate their prospective for solar cell applications.

Design and fabrication of NiCo2S4@rGO as an efficient Pt free triiodide reducing agent for dye-sensitized solar cell application

Exploiting efficient Pt-free counter-electrode materials with low cost and highly catalytic property is a hot topic in the field of Dye-sensitized solar cells (DSCs). Here, NiCo2S4/reduced graphene oxide (RGO) was prepared via an economical hydrothermal ynthesis route, and the as-prepared composite exhibited comparable electrocatalytic property with the conventional Pt electrode as the counter-electrode. Enhanced optoelectronic, optical and structural characteristics have been attained over the constructed heterojunction. Band gap energy of NiCo2S4 (2.35 eV) was suppressed to 2.11 eV owing to its supporting with 10 wt.% rGO bringing about upgraded absorption of visible light. Electrochemical studies confirmed the synergetic effect of nickel and cobalt ions with the high electrical conductive rGO networks that enhance the electrocatalytic activity of NiCo2S4 nanostructures. The efficiency achieved for the NiCo2S4@rGO counter electrode (CE) based DSSC is 8.17 %, which is remarkably higher than that of pristine NiCo2S4 (7.31 %), and Pt (7.14 %) under the same experimental conditions. In outline, given their innovative synthesis approach, affordability, and remarkable electrocatalytic attributes, the newly developed NiCo2S4@rGO counter electrodes stand out as potent contenders in future dye-sensitized solar cell applications.

Two-step preparation of methylammonium lead triiodide perovskite film via electrospray deposition of methylammonium iodide solution for solar cell applications

Two-step preparation of methylammonium lead triiodide perovskite film via electrospray deposition of methylammonium iodide solution for solar cell applications

Amorphous Cobalt-Impregnated Nitrogen-Doped Carbon Encapsulation Nanochain Enhances Long-Lasting Electrochemical Water Splitting.

Electrochemical water splitting (EWS) is a promising way to attain H2, which has been deemed an ideal substitution for fossil fuels because of renewable and eco-friendly benefits. Developing an amorphous-based simple and structurally flexible non-noble catalyst to offer high performance for commercial applications has become a current interest. Amorphous cobalt-anchored nitrogen-doped carbon nanoparticles (Co@NC-NPs) were designed to have a low overpotential and Tafel as a bifunctional electrocatalyst (HER - 142 mV/80 mV dec-1 and OER - 250 mV/72 mV dec-1) to achieve 10 mA cm-2 in 1.0 KOH. FE-SEM and HR-TEM described the interconnected nanochain morphology and purity of Co@NC-NPs electrocatalyst, which were confirmed by EDX and elemental mapping. In a full cell water electrolyzer, Co@NC-NPs(+,-) may act as an anode and cathode electrode material to achieve 1.60 V @ 10 mA cm-2 in a wide pH. The efficient Co@NC-NPs are stable for 100 h without obvious recession. In solar cell applications, Co@NC-NPs(+,-) catalyst was employed as both positive and negative terminals and evolved enormous bubbles of O2 and H2. As previously mentioned, we covered the amorphization strategy with the optimistic role of structural flexibility and defects to enrich the active sites to improve the electrocatalytic stability. As a promising opinion, the amorphous electrocatalyst provides ultraefficiency for forthcoming developments in EWS.

Exploring the Potential of Linear π-Bridge Structures in a D-π-A Organic Photosensitizer for Improved Open-Circuit Voltage.

We present the design, synthesis, and evaluation of novel metal-free photosensitizers based on D-π-A structures featuring tri-arylamine as an electron donor, cyanoacrylic acid as an anchoring group, and substituted derivative π-bridges including 9,9-dimethyl-9H-fluorene, benzo[b]thiophene, or naphtho [1,2-b:4,3-b']dithiophene. The aim of the current research is to unravel the relationship between chemical structure and photovoltaic performance in solar cell applications by investigating the properties of these organic sensitizers. The newly developed photosensitizers displayed variations in HOMO-LUMO energy gaps and photovoltaic performances due to their distinct π-bridge structures and exhibited diverse spectral responses ranging from 343 to 490 nm. The t-shaped and short linear photosensitizers demonstrated interesting behaviors in dye-sensitized solar cells, such as the effect of the molecular size in electron recombination. The study showed that a t-shaped photosensitizer with a bulky structure reduced electron recombination, while short linear photosensitizers with a smaller molecular size resulted in a higher open-circuit voltage value and enhanced photovoltaic performance. Impedance analysis further supported the findings, highlighting the influence of dye loading and I3- ion surface passivation on the overall performance of solar cells. The molecular design methodology proposed in this study enables promising photovoltaic performance in solar cells, addressing the demand for highly efficient, metal-free organic photosensitizers.

Simultaneously Improving Stretchability and Efficiency of Flexible Organic Solar Cells by Incorporating a Copolymer Interlayer in Active Layer

AbstractMechanical stretchability is a vital criterion for the wearable application of organic solar cells (OSCs), while the excessive rigidity of fused‐ring small molecular acceptors make the photovoltaic film hard to meet the stretchable requirements. Herein, an effective strategy is developed to construct an intrinsically stretchable active layer by inserting copolymer PM6‐b‐PYSe as an interlayer between layer‐by‐layer processed D18 and BTP‐eC9. The copolymer interlayer shunts the penetration of BTP‐eC9 and facilitates an appropriate phase separation, favoring the enhanced crack onset strain of 17.69% compared to the D18/BTP‐eC9 film (9.67%). Combining with the optimal energy levels, prolonged carrier lifetime, and suppressed bimolecular recombination aroused by the incorporation of PM6‐b‐PYSe, the D18/PM6‐b‐PYSe/BTP‐eC9‐based OSC yields an encouraging efficiency of 17.97%. In particular, the device demonstrates excellent mechanical property, which can retain over 80% after 4000 bending cycles. This work provides an effective strategy to simultaneously enhance the intrinsic mechanical stretchability and photovoltaic performance of flexible OSCs.

Exploring the structural, photophysical, and electrical properties of Dopant-Free hole transporting material based on 2, 7-carbazole from experimental to simulation

This paper presents the development of a dopant-free HTM as a thin film, utilizing carbazole (2,7) as a central building block. The deposition of homogeneous thin films of HTM2 was successfully achieved through Physical Vapor Deposition. The morphological, optical, and electrical properties of the fabricated samples were extensively studied using techniques such as Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), UV–visible spectroscopy, and Photoluminescence Technique. The AFM and SEM analyses demonstrated the uniformity and flatness of the thin film surfaces. The UV spectra results indicated that the maximum absorption spectra did not exhibit significant shifts when measured in chlorobenzene solvent, with an estimated band gap of approximately 2.96 eV. Photoluminescence spectroscopy and decay time measurements were conducted on HTM2 thin films, which revealed emission in the green-yellow region. The photoluminescence spectra of the thin films exhibited red-shifted emission bands compared to the solution, attributable to stronger π-π intermolecular interactions resulting in the closeness of the molecules in the solid state. This work finally couples the theoretical and experimental results to validate our obtained results and to get an idea about the efficiency of the cell-based HTM2. The obtained results confirmed that the investigated material can find applications in perovskite solar cells.