Developing cost-effective, high-efficiency, and stable hole transporting materials (HTMs) is crucial for replacing traditional spiro-OMeTAD in perovskite solar cells (PSCs) and achieving sustainable solar energy solutions. This work presents two novel air-stable HTMs based on a spiro[fluorene-9,9'-xanthene] (SFX) core functionalized with N-methylcarbazole (XC2-M) and N-hexylcarbazole (XC2-H) rings. These HTMs were synthesized via a straightforward, three-step process with good overall yields (∼40%) and low production costs.
View Article and Find Full Text PDFPolymers (Basel)
June 2024
In this work, four thymol-based benzoxazines were synthesized using four primary amines with different chain lengths, namely methylamine, ethylamine, 1-propylamine, and 1-butylamine, which are then named T-m, T-e, T-p, and T-b, respectively. The optical properties of the synthesized thymol-based benzoxazines were examined via the photoluminescent study of their solutions in acetone. The results show that all the prepared benzoxazines emitted blue light with the maximum wavelengths from 425 to 450 nm when irradiated by the excitation wavelengths from 275 to 315 nm.
View Article and Find Full Text PDFWith high efficacy for electron-photon conversion under low light, perovskite materials show great potential for indoor solar cell applications to power small electronics for internet of things (IoTs). To match the spectrum of an indoor LED light source, triple cation perovskite composition was varied to adjust band gap values via Cs and Br tuning. However, increased band gaps lead to morphology, phase instability, and defect issues.
View Article and Find Full Text PDFSci Rep
February 2024
High-quality VO[Formula: see text] films were fabricated on top of c-Al[Formula: see text]O[Formula: see text] substrates using Reactive Bias Target Ion Beam Deposition (RBTIBD) and the studies of graphene/VO[Formula: see text] heterostructure were conducted. Graphene layers were placed on top of [Formula: see text] 50 and [Formula: see text] 100 nm VO[Formula: see text]. The graphene layers were introduced using mechanical exfoliate and CVD graphene wet-transfer method to prevent the worsening crystallinity of VO[Formula: see text], to avoid the strain effect from lattice mismatch and to study how VO[Formula: see text] can affect the graphene layer.
View Article and Find Full Text PDFPerovskite materials are fascinating candidates for the next-generation solar devices. With long charge carrier lifetime, metal-halide perovskites are known to be good candidates for low-light harvesting. To match the irradiance spectra of indoor light, we configured a triple-cation perovskite material with appropriate content of bromide and chloride (FAMACsPb(IBrCl)) to achieve an optimum band gap (E) of [Formula: see text]1.
View Article and Find Full Text PDFIndustrial commercialization of perovskite solar cells not only depends on sufficient device performance, but also requires complete elimination of hazardous solvents in the fabrication process to enable sustainable development of the technology. This work reports a new solvent system based on sulfolane, [Formula: see text]-butyrolactone (GBL), and acetic acid (AcOH) as a significantly greener alternative to common but more hazardous solvents. Interestingly, this solvent system not only resulted in densely-packed perovskite layer of bigger crystal size and better crystallinity, the grain boundaries were found to be more rigid and highly conductive to electrical current.
View Article and Find Full Text PDFSolution-processed organic-inorganic hybrid perovskite solar cells are among the candidates to replace the traditional silicon solar cells due to their excellent power conversion efficiency (PCE). Despite this considerable progress, understanding the properties of the perovskite precursor solution is critical for perovskite solar cells (PSCs) to achieve high performance and reproducibility. However, the exploration of perovskite precursor chemistry and its effects on photovoltaic performances has been limited thus far.
View Article and Find Full Text PDFWith growing population, vertical spaces from skyscrapers are vast. Semi-transparent solar cells enable an effective pathway for vertical energy harvesting. With composition tunability, perovskite materials can be designed with different transparencies and colors.
View Article and Find Full Text PDFRapid advancements in perovskite materials have led to potential applications in various optoelectronic devices, such as solar cells, light-emitting diodes, and photodetectors. Due to good photoelectric properties, perovskite enables low-cost and comparable performance in terms of responsivity, detectivity, and speed to those of the silicon counterpart. In this work, we utilized triple cation perovskite, well known for its high performance, stability, and wide absorption range, which is crucial for broadband photodetector applications.
View Article and Find Full Text PDFAmong lanthanide-based compounds, cerium compounds exhibit a significant role in a variety of research fields due to their distinct tetravalency, high economic feasibility, and high stability of Ce(IV) complexes. Herein, a systematic investigation of crystallographic information, chemical properties, and mechanistic formation of the novel Ce(IV) complex synthesized from cerium(III) nitrate hexahydrate and 2,2'-(methylazanediyl)bis(methylene)bis(4-methylphenol) (MMD) ligand has been explored. According to the analysis of the crystallographic information, the obtained complex crystal consists of the Ce(IV) center coordinated with two nitrate ligands and two bidentate coordinated (-protonated and O,O-deprotonated) MMD ligands.
View Article and Find Full Text PDFGraphene and graphene-based hybrid materials have emerged as an outstanding supercapacitor electrode material primarily because of their excellent surface area, high electrical conductivity, and improved thermal, mechanical, electrochemical cycling stabilities. Graphene alone exhibits electric double layer capacitance (EDLC) with low energy density and high power density. The use of aerogels in a supercapacitor is a pragmatic approach due to its extraordinary properties like ultra-lightweight, high porosity and specific surface area.
View Article and Find Full Text PDFQuantum dot solar cells (QDSCs) are attractive technology for commercialization, owing to various advantages, such as cost effectiveness, and require relatively simple device fabrication processes. The properties of semiconductor quantum dots (QDs), such as band gap energy, optical absorption, and carrier transport, can be effectively tuned by modulating their size and shape. Two types of architectures of QDSCs have been developed: 1) photoelectric cells (PECs) fabricated from QDs sensitized on nanostructured TiO , and 2) photovoltaic cells fabricated from a Schottky junction and heterojunction.
View Article and Find Full Text PDF(PEA)(MA) Pb I Br perovskites are semi-transparent, color-tunable thin films with broader band gaps. They have the potential for semi-transparent solar cell and smart window applications. Solvent engineering significantly alters the morphology, absorbance, crystallinity, charge separation, and defects, thereby influencing the optoelectronic properties.
View Article and Find Full Text PDFJ Colloid Interface Sci
October 2018
Symmetric supercapacitor is advanced over simple supercapacitor device due to their stability over a large potential window and high energy density. Graphene is a desired candidate for supercapacitor application since it has a high surface area, good electronic conductivity and high electro chemical stability. There is a pragmatic use of ionic liquid electrolyte for supercapacitor due to its stability over a large potential window, good ionic conductivity and eco-friendly nature.
View Article and Find Full Text PDFDye-sensitized solar cells (DSSCs) have aroused great interest and been regarded as a potential renewable energy resource among the third-generation solar cell technologies to fulfill the 21 century global energy demand. DSSCs have notable advantages such as low cost, easy fabrication process and being eco-friendly in nature. The progress of DSSCs over the last 20 years has been nearly constant due to some limitations, like poor long-term stability, narrow absorption spectrum, charge carrier transportation and collection losses and poor charge transfer mechanism for regeneration of dye molecules.
View Article and Find Full Text PDFLangmuir monolayers of ligand-capped inorganic nanoparticles exhibit rich morphologies under lateral compression such as wrinkling, folding, and multilayer nucleation. We demonstrate that the ligands play a crucial role in the mechanical properties of nanoparticle films by probing the morphology and anisotropic stress response during lateral compression of films with systematically varied ligand concentrations. Increasing the ligand concentration of the films past a threshold value inhibits monolayer wrinkling and folding in favor of multilayer formation, and sharply reduces the compressive and shear moduli.
View Article and Find Full Text PDFOrganometal halide perovskites exhibit large bulk crystal domain sizes, rare traps, excellent mobilities and carriers that are free at room temperature-properties that support their excellent performance in charge-separating devices. In devices that rely on the forward injection of electrons and holes, such as light-emitting diodes (LEDs), excellent mobilities contribute to the efficient capture of non-equilibrium charge carriers by rare non-radiative centres. Moreover, the lack of bound excitons weakens the competition of desired radiative (over undesired non-radiative) recombination.
View Article and Find Full Text PDFThe density of trap states within the bandgap of methylammonium lead iodide single crystals is investigated. Defect states close to both the conduction and valence bands are probed. Additionally, a comprehensive electronic characterization of crystals is carried out, including measurements of the electron and hole mobility, and the energy landscape (band diagram) at the surface.
View Article and Find Full Text PDFA crosslinked hole-extracting electrical contact is reported, which simultaneously improves the stability and lowers the hysteresis of perovskite solar cells. Polymerizable monomers and crosslinking processes are developed to obviate in situ degradation of the under lying perovskite. The crosslinked material is band-aligned with perovskite.
View Article and Find Full Text PDFA solution-based passivation scheme is developed featuring the use of molecular iodine and PbS colloidal quantum dots (CQDs). The improved passivation translates into a longer carrier diffusion length in the solid film. This allows thicker solar-cell devices to be built while preserving efficient charge collection, leading to a certified power conversion efficiency of 9.
View Article and Find Full Text PDFNanocrystals of CsPbX3 perovskites are promising materials for light-emitting optoelectronics because of their colloidal stability, optically tunable bandgap, bright photoluminescence, and excellent photoluminescence quantum yield. Despite their promise, nanocrystal-only films of CsPbX3 perovskites have not yet been fabricated; instead, highly insulating polymers have been relied upon to compensate for nanocrystals' unstable surfaces. We develop solution chemistry that enables single-step casting of perovskite nanocrystal films and overcomes problems in both perovskite quantum dot purification and film fabrication.
View Article and Find Full Text PDFThe optoelectronic tunability offered by colloidal quantum dots (CQDs) is attractive for photovoltaic applications but demands proper band alignment at electrodes for efficient charge extraction at minimal cost to voltage. With this goal in mind, self-assembled monolayers (SAMs) can be used to modify interface energy levels locally. However, to be effective SAMs must be made robust to treatment using the various solvents and ligands required for to fabricate high quality CQD solids.
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