Publications by authors named "Piyasiri Ekanayake"

Hole transport material-free carbon-based perovskite solar cells (HTM-free -PSCs) are recognized as a cost-effective and stable alternative to conventional perovskite solar cells. However, the significant energy level misalignment between the perovskite layer and the carbon counter electrode (CE) results in ineffective hole extraction and unfavorable charge recombination, which decreases the power conversion efficiency (PCE). Here, we report the introduction of metal salts (Al, Ca, and Mg) into graphite/carbon black (Gr/CB) CEs to modify the work function and enhance the hole selectivity of the CE.

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The interfacial compatibility between the graphite/carbon black composite counter electrode (Gr/CB CE) and the perovskite layer is a crucial determinant of the performance of the hole-transport-layer-free carbon-based perovskite solar cells, and judicious selection of the Gr/CB CE application method is essential for achieving an optimum contact. In this work, three different types of Gr/CB CEs application methods are investigated: (1) deposition of Gr/CB on the fluorine-doped tin oxide (FTO) substrate, followed by clamping to the perovskite layer, (2) direct deposition of Gr/CB onto the perovskite layer, and (3) deposition of Gr/CB onto the PbI precursor layer, followed by immersion in methylammonium iodide solution for the conversion of PbI to perovskite. The results revealed that Method 3 produced superior Gr/CB-perovskite contacts, resulting in up to 8.

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In this article, we present the data collected from the fabricated carbon black-graphite counter electrode for dye-sensitized solar cells (DSSC) by incorporating binders such as titanium (IV) isopropoxide (TTIP), and zirconium (IV) dioxide (ZrO). The addition of binders to the carbon black-graphite composite (CB/Gr) can drastically improve the adherence between the counter electrodes and the fluorine-doped tin oxide (FTO) substrate, surface area and the interparticle connection between the carbon materials. These data are presented which comprise of the resistivity measurements, scanning electron microscopy (SEM) with energy dispersive X-ray (EDX), and near-edge X-ray absorption fine structure (NEXAFS).

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A high-purity methylammonium lead iodide complex with intercalated dimethylformamide (DMF) molecules, CH NH PbI ⋅DMF, is introduced as an effective precursor material for fabricating high-quality solution-processed perovskite layers. Spin-coated films of the solvent-intercalated complex dissolved in pure dimethyl sulfoxide (DMSO) yielded thick, dense perovskite layers after thermal annealing. The low volatility of the pure DMSO solvent extended the allowable time for low-speed spin programs and considerably relaxed the precision needed for the antisolvent addition step.

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The use of anthocyanin dyes extracted from epidermal leaves of Tradescantia spathacea (Trant) and petals of Ixora coccinea (IX) was evaluated in the application of dye-sensitized solar cells (DSSCs). Subsequently, cocktail anthocyanin dyes from these dyes were prepared and how they enhanced the cell's overall performance was assessed using five different volume-to-volume ratios. Cocktail dyes absorbed a wider range of light in the visible region, thus increasing the cell efficiencies of the cocktail dyes when compared to the DSSC sensitized by individual dyes.

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Chlorophyll and xanthophyll dyes extracted from a single source of filamentous freshwater green algae (Cladophora sp.) were used to sensitize dye sensitized solar cells and their performances were investigated. A more positive interaction is expected as the derived dyes come from a single natural source because they work mutually in nature.

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Possibility of use of dye extract from skin samples of a seasonal, indigenous fruit from Borneo, namely Canarium odontophyllum, in dye sensitized solar cells (DSSCs) are explored. Three main groups of flavonoid pigments are detected and these pigments exhibit different UV-vis absorption properties, and hence showing different light harvesting capabilities. When applied in DSSCs.

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Article Synopsis
  • * Three plant sources—Melastoma malabathricum (fruit pulp), Hibiscus rosa-sinensis (flower), and Codiaeum variegatum (leaves)—were identified as having the highest absorption capabilities and anthocyanin content, with Melastoma malabathricum leading at 8.43 mg/L.
  • * The stability of the anthocyanin pigments was significantly better at lower temperatures (4°C), with M. malabathricum demonstrating a notable photovoltaic efficiency of 1
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