59 documents found, page 1 of 6
Sub-Bandgap Sensitization of Perovskite Semiconductors via Colloidal Quantum Do...
Ribeiro, Guilherme; Ferreira, G.; Menda, U.D.; Alexandre, Miguel; Brites, Maria João; Barreiros, M. Alexandra; Jana, S.; Águas, Hugo; Martins, RodrigoABSTRACT: By taking advantage of the outstanding intrinsic optoelectronic properties of perovskite-based photovoltaic materials, together with the strong near-infrared (NIR) absorption and electronic confinement in PbS quantum dots (QDs), sub-bandgap photocurrent generation is possible, opening the way for solar cell efficiencies surpassing the classical limits. The present study shows an effective methodology ...
Contribution to the Understanding of the Colour Change in Bluish-Grey Limestones
Silva, Teresa; Oliveira, Daniel; Veiga, João Pedro; Lisboa, Vitor; Carvalho, Jorge; Barreiros, M. Alexandra; Coutinho, Mathilda; Salas-Colera, EduardoBluish-grey limestones have been extensively used as ornamental stones for decoration purposes in buildings, as well as in works of art, and accordingly, have been the target of intense exploration. In Portugal, the Jurassic limestone massif known as the Maciço Calcário Estremenho (MCE), has been the source of grey-coloured ornamental stones, namely the Azul Valverde (one of the most well-known bluish-grey lime...
Sub-Bandgap Sensitization of Perovskite Semiconductors via Colloidal Quantum Do...
Ribeiro, Guilherme; Ferreira, G.; Menda, U.D.; Alexandre, Miguel; Brites, Maria João; Barreiros, M. Alexandra; Jana, S.; Águas, Hugo; Martins, RodrigoABSTRACT: By taking advantage of the outstanding intrinsic optoelectronic properties of perovskite-based photovoltaic materials, together with the strong near-infrared (NIR) absorption and electronic confinement in PbS quantum dots (QDs), sub-bandgap photocurrent generation is possible, opening the way for solar cell efficiencies surpassing the classical limits. The present study shows an effective methodology ...
Looking into historical cracks analysing repaired silver objects by electron mi...
Tissot, Isabel; Barreiros, M. Alexandra; Lemos, Manuel; Tissot, MatthiasABSTRACT: The identification of structural alterations of silver alloy objects of cultural interest is essential to assess their state of conservation and define maintenance programmes. Alterations induced by previous repair and cleaning actions strongly affect the conservation condition, influencing the type and extension of conservation procedures. The detailed analysis of ancient repairs is a subject to be i...
Contribution to the Understanding of the Colour Change in Bluish-Grey Limestones
Silva, Teresa; De Oliveira, Daniel Pipa Soares; Veiga, JP; Lisboa, Jose; Carvalho, Jorge; Barreiros, M. Alexandra; Coutinho, ML; Salas-Colera, EduardoABSTRACT: Bluish-grey limestones have been extensively used as ornamental stones for decoration purposes in buildings, as well as in works of art, and accordingly, have been the target of intense exploration. In Portugal, the Jurassic limestone massif known as the Macico Calcario Estremenho (MCE), has been the source of grey-coloured ornamental stones, namely the Azul Valverde (one of the most well-known bluish...
Looking into historical cracks analysing repaired silver objects by electron mi...
Tissot, Isabel; Barreiros, M. Alexandra; Lemos, Manuel; Tissot, MatthiasABSTRACT: The identification of structural alterations of silver alloy objects of cultural interest is essential to assess their state of conservation and define maintenance programmes. Alterations induced by previous repair and cleaning actions strongly affect the conservation condition, influencing the type and extension of conservation procedures. The detailed analysis of ancient repairs is a subject to be i...
Contribution to the Understanding of the Colour Change in Bluish-Grey Limestones
Silva, Teresa; De Oliveira, Daniel Pipa Soares; Veiga, JP; Lisboa, Jose; Carvalho, Jorge; Barreiros, M. Alexandra; Coutinho, ML; Salas-Colera, EduardoABSTRACT: Bluish-grey limestones have been extensively used as ornamental stones for decoration purposes in buildings, as well as in works of art, and accordingly, have been the target of intense exploration. In Portugal, the Jurassic limestone massif known as the Macico Calcario Estremenho (MCE), has been the source of grey-coloured ornamental stones, namely the Azul Valverde (one of the most well-known bluish...
Slow pyrolysis of cork granules under nitrogen atmosphere: by-products characte...
Costa, Paula; Barreiros, M. Alexandra; Mouquinho, Ana; Silva, P. Oliveira e; Paradela, Filipe; Oliveira, Fernando Almeida CostaABSTRACT: Cork granules (Quercus suber L.) were slowly pyrolyzed at temperatures between 400-700 degrees C and under N-2 flow. While preserving its structure, some cells of the cork biochar became interconnected, allowing such carbon residue to be used as templates for manufacturing ceria redox materials. The pyrolytic char morphology was similar to that of the natural precursor. The produced cork biochar belon...
Perovskite Metal-Oxide-Semiconductor Structures for Interface Characterization
Cunha, J.M.V.; Barreiros, M. Alexandra; Curado, M.A.; Lopes, T.S.; Oliveira, K.; Oliveira, A.J.N.; Barbosa, J.R.S.; Vilanova, AntónioABSTRACT: Perovskite solar cells (PSCs) are one of the most promising photovoltaic technologies. Amongst several challenges, developing and optimizing efficient electron transport layers that can be up-scaled still remains a massive task. Admittance measurements on metal-oxide-semiconductor (MOS) devices allow to better understand the optoelectronic properties of the interface between perovskite and the charge ...
In-Depth Inhomogeneities in CIGS Solar Cells: Identifying Regions for Performan...
Corregidor, V.; Barreiros, M. Alexandra; Salomé, P.M.P.; Alves, L. C.ABSTRACT: When considering materials to be used as active layers in solar cells, an important required parameter is the proper knowledge of their elemental composition. It should be heavily controlled during growth in order to obtain the desired band gap and to decrease the recombination defects and then increase the solar cell electrical performance. Ion beam analytical (IBA) techniques and, in particular, par...