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10. Thermal-Carrier-Escape Mitigation in a Quantum-Dot-In-Perovskite Intermediate Band Solar Cell via Bandgap Engineering

Author

Menda, Ugur D., Ribeiro, Guilherme, Deuermeier, Jonas, López, Esther, Nunes, Daniela, Jana, Santanu, Artacho, Irene, Martins, Rodrigo, Mora-Seró, Iván, Mendes, Manuel J., and Ramiro, Iñigo

Subjects
Condensed Matter - Materials Science, Physics - Applied Physics
Abstract

By harvesting a wider range of the solar spectrum, intermediate band solar cells (IBSCs) can achieve efficiencies 50% higher than conventional single-junction solar cells. For this, additional requirements are imposed to the light-absorbing semiconductor, which must contain a collection of in-gap levels, called intermediate band (IB), optically coupled to but thermally decoupled from the valence and conduction bands (VB and CB). Quantum-dot-in-perovskite (QDiP) solids, where inorganic quantum dots (QDs) are embedded in a halide perovskite matrix, have been recently suggested as a promising material platform for developing IBSCs. In this work, QDiP solids with excellent morphological and structural quality and strong absorption and emission related to the presence of in-gap QD levels are synthesized. With them, QDiP-based IBSCs are fabricated and, by means of temperature-dependent photocurrent measurements, it is shown that the IB is strongly thermally decoupled from the valence and conduction bands. The activation energy of the IB$\rightarrow$CB thermal escape of electrons is measured to be 204 meV, resulting in the mitigation of this detrimental process even under room-temperature operation, thus fulfilling the first mandatory requisite to enable high-efficiency IBSCs.

Published
2023
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12. Influence of different carrier gases on the properties of ZnO films grown by MOCVD

Author

Wang, Jinzhong, Elamurugu, Elangovan, Sallet, Vincent, Lusson, Alain, Amiri, Gaëlle, Jomard, François, Martins, Rodrigo, and Fortunato, Elvira

Subjects
ZnO thin films, MOCVD, SIMS profile, PL spectra, Estructura Capas delgadas de ZnO, MOCVD, perfil de SIMS, espectro PL, Clay industries. Ceramics. Glass, TP785-869
Abstract

ZnO films were grown on sapphire (001) substrate by atmospheric MOCVD using diethyl zinc and tertiary butanol precursors. The influence of different carrier gases (H2 and He) on the properties was analyzed by their structural (XRD), microstructural (SEM) and compositional (SIMS) characterization. The intensity of the strongest diffraction peak from ZnO (002) plane was increased by about 2 orders of magnitude when He is used as carrier gas, indicating the significant enhancement in crystallinity. The surface of the samples grown using H2 and He carrier gases was composed of leaf-like and spherical grains respectively. Hydrogen [H] content in the film grown using H2 is higher than that using He, indicating that the [H] was influenced by the H2 carrier gas. Ultraviolet emission dominates the low temperature PL spectra. The emission from ZnO films grown using He show higher optical quality and more emission centers.Se depositaron películas de ZnO sobre sustratos de zafiro (001) utilizando dietil zinc y butanol terciario como precursores. La influencia de los diferentes gases portadores (H2 y He) sobre las propiedades se estudió mediante la caracterización estructural (XRD), microestructural (SEM) y composicional (SIMS). La intensidad del pico de difracción más importante del plano (002) del ZnO aumentó en dos órdenes de magnitud cuando se utiliza He como gas portador indicando un incremento significativo de la cristalinidad. La superficie de las muestras crecidas utilizando H2 y He está formada por granos en forma de hoja y de forma esférica respectivamente. El contenido en hidrógeno (H) en la película es mayor cuando se utiliza H2 que cuando se utiliza He, indicando que la cantidad de hidrógeno está influenciada por el H2 del gas portador. La emisión ultravioleta domina el espectro PL de baja temperatura. La emisión de las películas de ZnO utilizando He muestra mayor calidad óptica y más centros de emisión.

Published
2008

31. Chapter 3 Optoelectronics and Bio Devices on Paper Powered by Solar Cells

Author

Vicente, António T., Araújo, Andreia, Gaspar, Diana, Santos, Lídia, Marques, Ana C., Mendes, Manuel J., Pereira, Luís, Fortunato, Elvira, and Martins, Rodrigo

Subjects
cellulose, optoelectronic and bio devices, paper characterization, inkjet, printing, solar cells on paper substrates, Coating, bic Book Industry Communication::A The arts, bic Book Industry Communication::C Language::CF linguistics::CFL Palaeography (history of writing)::CFLA Writing systems, alphabets, bic Book Industry Communication::C Language::CF linguistics::CFX Computational linguistics
Abstract

The employment of printing techniques as cost-effective methods to fabricate low cost, flexible, disposable and sustainable solar cells is intimately dependent on the substrate properties and the adequate electronic devices to be powered by them. Among such devices, there is currently a growing interest in the development of user-oriented and multipurpose systems for intelligent packaging or on-site medical diagnostics, which would greatly benefit from printable solar cells as their energy source for autonomous operation. This chapter first describes and analyzes different types of cellulose-based substrates for flexible and cost effective optoelectronic and bio devices to be powered by printed solar cells. Cellulose is one of the most promising platforms for green recyclable electronics and it is fully compatible with large-scale printing techniques, although some critical requirements must be addressed. Paper substrates exist in many forms. From common office paper, to packaging cardboard used in the food industry, or nanoscale engineered cellulose (e.g. bacterial cellulose). However, it is the structure and content of paper that determines its end use. Secondly, proof-of-concept of optoelectronic and bio devices produced by inkjet printing are described and show the usefulness of solar cells as a power source or as a chemical reaction initiator for sensors.

Published
2017
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32. Accuracy Assessments of Stochastic and Deterministic Interpolation Methods in Estimating Soil Attributes Spatial Variability

Author

Martins, Rodrigo Nogueira, Dos Santos, Fernando Ferreira Lima, De Moura Araújo, Guilherme, De Arruda Viana, Lucas, and Rosas, Jorge Tadeu Fim

Subjects
Bioengineering, Ordinary kriging, inverse distance weighting, geostatistics, precision agriculture, Soil Sciences, Plant Biology, Crop and Pasture Production, Agronomy & Agriculture
Abstract

Spatial interpolation methods are frequently used to characterize soil attributes’ spatial variability. However, inconclusive results, about the comparative performance of these methods, have been reported in the literature. Therefore, the present study aimed to analyze the efficiency of ordinary kriging (OK) and inverse distance weighting (IDW) methods in estimating the soil penetration resistance (SPR), soil bulk density (SBD), and soil moisture content (SM) using two distinct sampling grids. The soil sampling was performed on a 5.7 ha area in Southeast Brazil. For data collection, a regular grid with 145 points (20 x 20 m) was created. Soil samples were taken at a 0.20 m layer depth. In order to compare the accuracy of OK and IDW, another grid was created from the initial grid (A), by eliminating one interspersed line, which resulted in a grid with 41 sampled points (40 x 40 m). Results showed that sampling grid A presented less errors than B, proving that the more sampling points, the lower the errors that are associated with both methods will be. Overall, the OK was less biased than IDW only for SBD (A) and SM (B) maps, whereas IDW outperformed OK for the other attributes for both sampling grids.

Published
2019

34. Chapter Porous ZnO Nanostructures Synthesized by Microwave Hydrothermal Method for Energy Harvesting Applications

Author

Dos Santos, Andreia, Henriques Ferreira, Sofia, Rovisco, Ana, Águas, Hugo, Igreja, Rui, Barquinha, Pedro, Fortunato, Elvira, and Martins, Rodrigo

Subjects
Materials science, thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGM Materials science
Abstract

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Published
2021
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37. The Resilience of the Aquatic Isoëtes Cangae to Terrestrial Environment: Insights Into Molecular and Ecophysiological Adaptations

Author

de Sant’anna Lopes, Arthur Vinícius, Neto, Lupis Ribeiro Gomes, Cogo, Antonio Jesus Dorighetto, Cunha, Luigi Pereira, Caldeira, Cecílio Frois, Oliveira, Guilherme, Martins, Rodrigo Lemes, de Assis Esteves, Francisco, Cavalcante, Allysson Buraslan, Duarte, Heitor Monteiro, Zandonadi, Daniel Basílio, da Fonseca, Rodrigo Nunes, and Santos, Mirella Pupo

Published
2023
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43. Pou4f2/Brn3b Overexpression Promotes The Genesis Of Retinal Ganglion Cell-Like Projection Neurons From Late Progenitors

Author

Oliveira-Valenca, Viviane Medeiros, primary, Roberts, Jacqueline M., additional, Fernandes-Cerqueira, Vitoria M., additional, Colmerauer, Carolina H., additional, de Toledo, Beatriz Cardoso, additional, Santos-Franca, Pedro Lucas, additional, Linden, Rafael, additional, Martins, Rodrigo A. P., additional, Rocha-Martins, Mauricio, additional, Bosco, Alejandra, additional, Vetter, Monica L., additional, and Silveira, Mariana S, additional

Published
2024
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47. Analyzing the correlation between body composition variables and cellular phase angle via computerized bioelectrical impedance analysis (BIA)

Author

Lopes-Martins, Rodrigo Alvaro Brandão, primary, Moraes Gomes, Gabriela, additional, Ricardo Pinheiro França, Paulo, additional, Miguel de Jesus Pereira, Pablo, additional, Batista Souza, Nicolle, additional, Soares de Araújo Junior, Osvaldo, additional, Gomes dos Santos, Larissa, additional, Eduarda Nunes Silva, Maria, additional, Sardinha Leonardo Lopes Martins, Pedro, additional, Sardinha Leonardo, Patrícia, additional, and Castro Quiuli, Andria, additional

Published
2024
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