Publications by authors named "Ronan O"

3 Publications

  • Page 1 of 1

Inclusion of 2D Transition Metal Dichalcogenides in Perovskite Inks and Their Influence on Solar Cell Performance.

Nanomaterials (Basel) 2021 Jun 29;11(7). Epub 2021 Jun 29.

CNR NANOTEC, c/o Campus Ecotekne, Institute of Nanotechnology, Via Monteroni, 73100 Lecce, Italy.

Organic-inorganic hybrid perovskite materials have raised great interest in recent years due to their excellent optoelectronic properties, which promise stunning improvements in photovoltaic technologies. Moreover, two-dimensional layered materials such as graphene, its derivatives, and transition metal dichalcogenides have been extensively investigated for a wide range of electronic and optoelectronic applications and have recently shown a synergistic effect in combination with hybrid perovskite materials. Here, we report on the inclusion of liquid-phase exfoliated molybdenum disulfide nanosheets into different perovskite precursor solutions, exploring their influence on final device performance. We compared the effect of such additives upon the growth of diverse perovskites, namely CHNHPbI (MAPbI) and triple-cation with mixed halides Cs (MAFA)Pb (IBr) perovskite. We show how for the referential MAPbI materials the addition of the MoS additive leads to the formation of larger, highly crystalline grains, which result in a remarkable 15% relative improvement in power conversion efficiency. On the other hand, for the mixed cation-halide perovskite no improvements were observed, confirming that the nucleation process for the two materials is differently influenced by the presence of MoS.
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http://dx.doi.org/10.3390/nano11071706DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8308140PMC
June 2021

Additive-free MXene inks and direct printing of micro-supercapacitors.

Nat Commun 2019 04 17;10(1):1795. Epub 2019 Apr 17.

CRANN and AMBER Research Centers, Trinity College Dublin, Dublin 2, Ireland.

Direct printing of functional inks is critical for applications in diverse areas including electrochemical energy storage, smart electronics and healthcare. However, the available printable ink formulations are far from ideal. Either surfactants/additives are typically involved or the ink concentration is low, which add complexity to the manufacturing and compromises the printing resolution. Here, we demonstrate two types of two-dimensional titanium carbide (TiCT) MXene inks, aqueous and organic in the absence of any additive or binary-solvent systems, for extrusion printing and inkjet printing, respectively. We show examples of all-MXene-printed structures, such as micro-supercapacitors, conductive tracks and ohmic resistors on untreated plastic and paper substrates, with high printing resolution and spatial uniformity. The volumetric capacitance and energy density of the all-MXene-printed micro-supercapacitors are orders of magnitude greater than existing inkjet/extrusion-printed active materials. The versatile direct-ink-printing technique highlights the promise of additive-free MXene inks for scalable fabrication of easy-to-integrate components of printable electronics.
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http://dx.doi.org/10.1038/s41467-019-09398-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6470171PMC
April 2019

Enabling Flexible Heterostructures for Li-Ion Battery Anodes Based on Nanotube and Liquid-Phase Exfoliated 2D Gallium Chalcogenide Nanosheet Colloidal Solutions.

Small 2017 09 10;13(34). Epub 2017 Jul 10.

Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and Advanced Materials Bio-Engineering Research Centre (AMBER), Trinity College Dublin, Dublin 2, Ireland.

2D metal chalcogenide (MC) nanosheets (NS) have displayed high capacities as lithium-ion battery (LiB) anodes. Nevertheless, their complicated synthesis routes coupled with low electronic conductivity greatly limit them as promising LiB electrode material. Here, this work reports a facile single-walled carbon nanotube (SWCNT) percolating strategy for efficiently maximizing the electrochemical performances of gallium chalcogenide (GaX, X = S or Se). Multiscaled flexible GaX NS/SWCNT heterostructures with abundant voids for Li diffusion are fabricated by embedding the liquid-exfoliated GaX NS matrix within a SWCNT-percolated network; the latter improves the electron transport and ion diffusion kinetics as well as maintains the mechanical flexibility. Consequently, high capacities (i.e., 838 mAh g per gallium (II) sulfide (GaS) NS/SWCNT mass and 1107 mAh g per GaS mass; the latter is close to the theoretical value) and good rate capabilities are achieved, which can be majorly attributed to the alloying processes of disordered Ga formed after the first irreversible GaX conversion reaction, as monitored by in situ X-ray diffraction. The presented approach, colloidal solution processing of SWCNT and liquid-exfoliated MC NS to produce flexible paper-based electrode, could be generalized for wearable energy storage devices with promising performances.
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http://dx.doi.org/10.1002/smll.201701677DOI Listing
September 2017
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