Quantum dots (QDs) are inorganic semiconductor particles that exhibit size and shape dependent op... more Quantum dots (QDs) are inorganic semiconductor particles that exhibit size and shape dependent optical and electronic properties. Due to the typical dimension in the range of 1-100 nm, the surface-to-volume ratios of the materials become large and their electronic states become discrete. Moreover, due to the fact that the size of the semiconductor nanocrystal is smaller than the size of the exciton, charge carriers become spatially confined, which raises their energy (quantum confinement). Thus, the size and shape-dependent optoelectronic properties are attributed to the quantum confinement effect. Because of this effect, light emission from these particles can be tuned, throughout the ultraviolet, visible and near infrared spectral ranges. Quantum dots possess many advantages that make them interesting for several applications: They show symmetrical and narrow emission spectra and broad absorption spectra, enabling that a single light source can be used to excite multicolour quantu...
We present a simple, low-cost, pioneering technique for the metallization of polymeric substrates... more We present a simple, low-cost, pioneering technique for the metallization of polymeric substrates that allows manufacturing of 3D-PCBs for fully encapsulated Smart Systems. This 3D packaging approach provides a compact solution to integrate MEMs with fluidics in a durable substrate, opening the door to adapting Smart Systems to harsh environments of vibration and temperature
Quantum dot-hydrotalcite layered nanoplatforms were successfully prepared following a one-pot syn... more Quantum dot-hydrotalcite layered nanoplatforms were successfully prepared following a one-pot synthesis. The process is very fast and a priori delamination of hydrotalcite is not a prerequisite for the intercalation of quantum dots. The novel materials were extensively characterized by X-ray diffraction, thermogravimetry, infrared spectroscopy, transmission electron microscopy, true color fluorescence microscopy, photoluminescence, and nitrogen adsorption. The quantum dot-hydrotalcite nanomaterials display extremely high stability in mimicking physiological media such as saline serum (pH 5.5) and PBS (pH 7.2). Yet, quantum dot release from the solid structure is noted. In order to prevent the leaking of quantum dots we have developed a novel strategy which consists of using tailor made double layered hydrotalcites as protecting shells for quantum dots embedded into silica nanospheres without changing either the materials or the optical properties.
Since the demonstration of efficient hybrid photovoltaic devices using CdSe/P3HT, a number of dif... more Since the demonstration of efficient hybrid photovoltaic devices using CdSe/P3HT, a number of different QD/polymer molecular solar cells have been investigated. However, considerably less attention has been paid to the photo-induced processes occurring in these devices, in particular the strong dependence that device efficiencies show upon QD concentration. This study aims to shed more light on this dependence by monitoring these processes occurring at the QD/polymer interface, namely, exciton formation, charge separation and undesired charge recombination.
Organic polymer solar cells (OPSCs) have been prepared using TiO(x) metal oxides as selective ele... more Organic polymer solar cells (OPSCs) have been prepared using TiO(x) metal oxides as selective electrodes for electron collection. The interfacial charge transfer reactions, under working conditions, that limit the energy conversion efficiency of these devices have been measured and compared to the standard OPSC geometry which collects the electrons through a low work function metal contact.
Quantum dots (QDs) are inorganic semiconductor particles that exhibit size and shape dependent op... more Quantum dots (QDs) are inorganic semiconductor particles that exhibit size and shape dependent optical and electronic properties. Due to the typical dimension in the range of 1-100 nm, the surface-to-volume ratios of the materials become large and their electronic states become discrete. Moreover, due to the fact that the size of the semiconductor nanocrystal is smaller than the size of the exciton, charge carriers become spatially confined, which raises their energy (quantum confinement). Thus, the size and shape-dependent optoelectronic properties are attributed to the quantum confinement effect. Because of this effect, light emission from these particles can be tuned, throughout the ultraviolet, visible and near infrared spectral ranges. Quantum dots possess many advantages that make them interesting for several applications: They show symmetrical and narrow emission spectra and broad absorption spectra, enabling that a single light source can be used to excite multicolour quantu...
We present a simple, low-cost, pioneering technique for the metallization of polymeric substrates... more We present a simple, low-cost, pioneering technique for the metallization of polymeric substrates that allows manufacturing of 3D-PCBs for fully encapsulated Smart Systems. This 3D packaging approach provides a compact solution to integrate MEMs with fluidics in a durable substrate, opening the door to adapting Smart Systems to harsh environments of vibration and temperature
Quantum dot-hydrotalcite layered nanoplatforms were successfully prepared following a one-pot syn... more Quantum dot-hydrotalcite layered nanoplatforms were successfully prepared following a one-pot synthesis. The process is very fast and a priori delamination of hydrotalcite is not a prerequisite for the intercalation of quantum dots. The novel materials were extensively characterized by X-ray diffraction, thermogravimetry, infrared spectroscopy, transmission electron microscopy, true color fluorescence microscopy, photoluminescence, and nitrogen adsorption. The quantum dot-hydrotalcite nanomaterials display extremely high stability in mimicking physiological media such as saline serum (pH 5.5) and PBS (pH 7.2). Yet, quantum dot release from the solid structure is noted. In order to prevent the leaking of quantum dots we have developed a novel strategy which consists of using tailor made double layered hydrotalcites as protecting shells for quantum dots embedded into silica nanospheres without changing either the materials or the optical properties.
Since the demonstration of efficient hybrid photovoltaic devices using CdSe/P3HT, a number of dif... more Since the demonstration of efficient hybrid photovoltaic devices using CdSe/P3HT, a number of different QD/polymer molecular solar cells have been investigated. However, considerably less attention has been paid to the photo-induced processes occurring in these devices, in particular the strong dependence that device efficiencies show upon QD concentration. This study aims to shed more light on this dependence by monitoring these processes occurring at the QD/polymer interface, namely, exciton formation, charge separation and undesired charge recombination.
Organic polymer solar cells (OPSCs) have been prepared using TiO(x) metal oxides as selective ele... more Organic polymer solar cells (OPSCs) have been prepared using TiO(x) metal oxides as selective electrodes for electron collection. The interfacial charge transfer reactions, under working conditions, that limit the energy conversion efficiency of these devices have been measured and compared to the standard OPSC geometry which collects the electrons through a low work function metal contact.
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Papers by Roberto Pacios