http://hdl.handle.net/2117/5574 Sun, 19 May 2013 08:45:42 GMT 2013-05-19T08:45:42Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/18126 Title: Influence of wavelength on laser doping and laser-fired contact processes for c-Si solar cells Authors: Molpeceres Alvarez, Carlos; Sanchez Aniorte, Maria Isabel; Morales, Miguel; Muñoz, David; Martín García, Isidro; Ortega Villasclaras, Pablo Rafael; Colina Brito, Mónica Alejandra; Voz Sánchez, Cristóbal; Alcubilla González, Ramón Abstract: This work investigates the influence of the laser wavelength on laser doping (LD) and laser - fired contact (LFC) formation in solar cell structures . We compare the results obtained using the three first harmonics (corresponding to wavelengths of 1064 nm, 532 nm and 355 nm) of fully commercial solid state laser sources with pulse width in the ns range. The discussion is based on the impact on the morphology and electrical characteristics of test structures. In the case of LFC the study includes th e influence of different passivation layers and the assessment of the process quality through electrical resistance measurements of an alumin i um single LFC point for the different wavelengths. Values for the normalized LFC resistance far below 1 .0 m Ω cm 2 have been obtained, with better results at s horter wavelen g ths. To assess the influence of the laser wavelength on LD we have created n+ regions into p - type c - Si wafers , using a dry LD approach to define punctual emitters. J - V characteristics show exponen tial trends at mid - injection for a broad parametric window in all wavelengths, with local ideality factors well below 1.5. In bot h processes the best results have been obtained using green (532 nm) and , specially, UV (355 nm) . This indicates that to minim ize the thermal damage in the material is a clear requisite to obtain th e best electrical performance, thus indicating that UV laser shows better potential to be used in high efficiency solar cells. Thu, 07 Mar 2013 12:32:31 GMT http://hdl.handle.net/2117/18126 2013-03-07T12:32:31Z Molpeceres Alvarez, Carlos; Sanchez Aniorte, Maria Isabel; Morales, Miguel; Muñoz, David; Martín García, Isidro; Ortega Villasclaras, Pablo Rafael; Colina Brito, Mónica Alejandra; Voz Sánchez, Cristóbal; Alcubilla González, Ramón no This work investigates the influence of the laser wavelength on laser doping (LD) and laser - fired contact (LFC) formation in solar cell structures . We compare the results obtained using the three first harmonics (corresponding to wavelengths of 1064 nm, 532 nm and 355 nm) of fully commercial solid state laser sources with pulse width in the ns range. The discussion is based on the impact on the morphology and electrical characteristics of test structures. In the case of LFC the study includes th e influence of different passivation layers and the assessment of the process quality through electrical resistance measurements of an alumin i um single LFC point for the different wavelengths. Values for the normalized LFC resistance far below 1 .0 m Ω cm 2 have been obtained, with better results at s horter wavelen g ths. To assess the influence of the laser wavelength on LD we have created n+ regions into p - type c - Si wafers , using a dry LD approach to define punctual emitters. J - V characteristics show exponen tial trends at mid - injection for a broad parametric window in all wavelengths, with local ideality factors well below 1.5. In bot h processes the best results have been obtained using green (532 nm) and , specially, UV (355 nm) . This indicates that to minim ize the thermal damage in the material is a clear requisite to obtain th e best electrical performance, thus indicating that UV laser shows better potential to be used in high efficiency solar cells. http://hdl.handle.net/2117/18059 Title: Lumogen violet dye as luminiscent down-shifting layer for C-silicon solar cells Authors: Ahmed, H.; Kennedy, M.; Confrey, T.; Doran, J.; McCormack, S.J.; Galindo Lorente, Sergi; Voz Sánchez, Cristóbal; Puigdollers i González, Joaquim Abstract: In this investigation Naphtalimide based Lumogen Violet organic dye [BASF] is characterized for inclusion in luminescent downshifting (LDS) layers. A PV device made up of an LDS layer of Lumogen Violet deposited on top of a crystalline silicon cell has been fabricated to improve its power conversion efficiency. External quantum efficiency measurements and outdoor tests for the PV/LDS devices are discussed. An analytical model was also developed to compare experiment results with the model predictions. Tue, 05 Mar 2013 11:16:34 GMT http://hdl.handle.net/2117/18059 2013-03-05T11:16:34Z Ahmed, H.; Kennedy, M.; Confrey, T.; Doran, J.; McCormack, S.J.; Galindo Lorente, Sergi; Voz Sánchez, Cristóbal; Puigdollers i González, Joaquim no In this investigation Naphtalimide based Lumogen Violet organic dye [BASF] is characterized for inclusion in luminescent downshifting (LDS) layers. A PV device made up of an LDS layer of Lumogen Violet deposited on top of a crystalline silicon cell has been fabricated to improve its power conversion efficiency. External quantum efficiency measurements and outdoor tests for the PV/LDS devices are discussed. An analytical model was also developed to compare experiment results with the model predictions. http://hdl.handle.net/2117/18055 Title: Ephocell project: smart light collecting system for the efficiency enhancement of solar cells - ray trace modeling of system Authors: Aubouy, Laurent; Gutiérrez-Tauste, D.; Della Pirriera, Monica; Noriega, G.; Di Lorenzo, M.L.; Avella, M.; Errico, M.E.; Gentile, G.; Kennedy, M.; Doran, J.; Norton, B.; Ahmed, H.; Baluschev, S.; Bistué Guardiola, J.; Hervera, F.; Puigdollers i González, Joaquim; Voz Sánchez, Cristóbal; Daren, S.; Solomon-Tsvetkov, F.; Pashov, A. Abstract: PV cell efficiency is limited partly due to the spectral mismatch between the solar spectrum and the PV absorption properties. PV conversion efficiency is enhanced by external modulation of the incident irradiance, by means of photon downshifting (DS) and upconversion (UC). A ray-trace modelling tool is presented to simulate the luminescent DS and UC processes and thereby optimise the doping concentrations and geometric dimensions of the DS and UC layers. Tue, 05 Mar 2013 11:02:48 GMT http://hdl.handle.net/2117/18055 2013-03-05T11:02:48Z Aubouy, Laurent; Gutiérrez-Tauste, D.; Della Pirriera, Monica; Noriega, G.; Di Lorenzo, M.L.; Avella, M.; Errico, M.E.; Gentile, G.; Kennedy, M.; Doran, J.; Norton, B.; Ahmed, H.; Baluschev, S.; Bistué Guardiola, J.; Hervera, F.; Puigdollers i González, Joaquim; Voz Sánchez, Cristóbal; Daren, S.; Solomon-Tsvetkov, F.; Pashov, A. no PV cell efficiency is limited partly due to the spectral mismatch between the solar spectrum and the PV absorption properties. PV conversion efficiency is enhanced by external modulation of the incident irradiance, by means of photon downshifting (DS) and upconversion (UC). A ray-trace modelling tool is presented to simulate the luminescent DS and UC processes and thereby optimise the doping concentrations and geometric dimensions of the DS and UC layers. http://hdl.handle.net/2117/17662 Title: Low recombination n+ regions created by n+ c-Si epitaxial layers and laser processing of phosphorus-doped SiCx films Authors: Martín García, Isidro; Colina Brito, Mónica Alejandra; Orpella García, Alberto; Voz Sánchez, Cristóbal; De Vecchi, S.; Desrues, T.; Abolmasov, S.; Roca i Cabarrocas, P.; Alcubilla González, Ramón Tue, 12 Feb 2013 13:48:15 GMT http://hdl.handle.net/2117/17662 2013-02-12T13:48:15Z Martín García, Isidro; Colina Brito, Mónica Alejandra; Orpella García, Alberto; Voz Sánchez, Cristóbal; De Vecchi, S.; Desrues, T.; Abolmasov, S.; Roca i Cabarrocas, P.; Alcubilla González, Ramón no http://hdl.handle.net/2117/17661 Title: Optimization of laser doping processes for the creation of p+ regions from solid dopant sources Authors: Colina Brito, Mónica Alejandra; Martín García, Isidro; Voz Sánchez, Cristóbal; Morales Vilches, Ana Belén; Ortega Villasclaras, Pablo Rafael; López Rodríguez, Gema; Orpella García, Alberto; Alcubilla González, Ramón; Sanchez Aniorte, Maria Isabel; Molpeceres Alvarez, Carlos Tue, 12 Feb 2013 13:44:38 GMT http://hdl.handle.net/2117/17661 2013-02-12T13:44:38Z Colina Brito, Mónica Alejandra; Martín García, Isidro; Voz Sánchez, Cristóbal; Morales Vilches, Ana Belén; Ortega Villasclaras, Pablo Rafael; López Rodríguez, Gema; Orpella García, Alberto; Alcubilla González, Ramón; Sanchez Aniorte, Maria Isabel; Molpeceres Alvarez, Carlos no http://hdl.handle.net/2117/17660 Title: Optimization of al2o3 films obtained by ald to passivate p-type c-silicon wafers Authors: López Rodríguez, Gema; Ortega Villasclaras, Pablo Rafael; Martín García, Isidro; Colina Brito, Mónica Alejandra; Orpella García, Alberto; Alcubilla González, Ramón Tue, 12 Feb 2013 13:42:12 GMT http://hdl.handle.net/2117/17660 2013-02-12T13:42:12Z López Rodríguez, Gema; Ortega Villasclaras, Pablo Rafael; Martín García, Isidro; Colina Brito, Mónica Alejandra; Orpella García, Alberto; Alcubilla González, Ramón no http://hdl.handle.net/2117/17658 Title: Influence of laser wavelength on laser-fired contacts for crystalline silicon solar cells Authors: Sanchez Aniorte, Maria Isabel; Muñoz Martín, D.; Morales, M.; Ortega Villasclaras, Pablo Rafael; Martín García, Isidro; Colina Brito, Mónica Alejandra; Alcubilla González, Ramón; Molpeceres Alvarez, Carlos Tue, 12 Feb 2013 13:37:44 GMT http://hdl.handle.net/2117/17658 2013-02-12T13:37:44Z Sanchez Aniorte, Maria Isabel; Muñoz Martín, D.; Morales, M.; Ortega Villasclaras, Pablo Rafael; Martín García, Isidro; Colina Brito, Mónica Alejandra; Alcubilla González, Ramón; Molpeceres Alvarez, Carlos no http://hdl.handle.net/2117/16050 Title: Adjust of solar cell model parameters based in MATLAB Authors: Silvestre Bergés, Santiago; Guasch Murillo, Daniel; Ortega Villasclaras, Pablo Rafael; Navarro Mas, Nacho Abstract: In this work, a model parameter extractor of solar cells using Matlab is shown. The software, developed in Matlab environment, has been successfully applied to study internal characteristics of photovoltaic devices [1-2], as well as on-line photovoltaic system performance [3-4]. However, in this case, the developed tool allows to obtain automatically electrical parameters than are often requested to model the performance of single solar cells, as can be the photocurrent density Jph, series resistance Rs, shunt resistance Rsh, saturation current Io, and ideality factor n. Parameters of a second diode, that takes into account recombination losses, as can be the saturation current Iorec and ideality factor nrec, are also included . Special attention has been focused on the extimation of the series resistance Rs, and the evolution of this parameter in dark and illumination work conditions of the solar cell. Thu, 14 Jun 2012 16:48:37 GMT http://hdl.handle.net/2117/16050 2012-06-14T16:48:37Z Silvestre Bergés, Santiago; Guasch Murillo, Daniel; Ortega Villasclaras, Pablo Rafael; Navarro Mas, Nacho no In this work, a model parameter extractor of solar cells using Matlab is shown. The software, developed in Matlab environment, has been successfully applied to study internal characteristics of photovoltaic devices [1-2], as well as on-line photovoltaic system performance [3-4]. However, in this case, the developed tool allows to obtain automatically electrical parameters than are often requested to model the performance of single solar cells, as can be the photocurrent density Jph, series resistance Rs, shunt resistance Rsh, saturation current Io, and ideality factor n. Parameters of a second diode, that takes into account recombination losses, as can be the saturation current Iorec and ideality factor nrec, are also included . Special attention has been focused on the extimation of the series resistance Rs, and the evolution of this parameter in dark and illumination work conditions of the solar cell. http://hdl.handle.net/2117/15703 Title: Fast time-to-market with via-configurable transistor array regular fabric: A delay-locked loop design case study Authors: González Colás, Antonio María; Pons Solé, Marc; Barajas Ojeda, Enrique; Mateo Peña, Diego; López González, Juan Miguel; Moll Echeto, Francisco de Borja; Rubio Sola, Jose Antonio; Abella Ferrer, Jaume; Vera Rivera, Francisco Javier Abstract: Time-to-market is a critical issue for nowadays integrated circuits manufacturers. In this paper the Via-Configurable Transistor Array regular layout fabric (VCTA), which aims to minimize the time-to-market and its associated costs, is studied for a Delay-Locked Loop design (DLL). The comparison with a full custom design demonstrates that VCTA can be used without loss of functionality while accelerating the design time. Layout implementations, in 90 nm CMOS process, as well as the delay, energy and jitter electrical simulations are provided. Tue, 03 Apr 2012 18:06:02 GMT http://hdl.handle.net/2117/15703 2012-04-03T18:06:02Z González Colás, Antonio María; Pons Solé, Marc; Barajas Ojeda, Enrique; Mateo Peña, Diego; López González, Juan Miguel; Moll Echeto, Francisco de Borja; Rubio Sola, Jose Antonio; Abella Ferrer, Jaume; Vera Rivera, Francisco Javier no Time-to-market is a critical issue for nowadays integrated circuits manufacturers. In this paper the Via-Configurable Transistor Array regular layout fabric (VCTA), which aims to minimize the time-to-market and its associated costs, is studied for a Delay-Locked Loop design (DLL). The comparison with a full custom design demonstrates that VCTA can be used without loss of functionality while accelerating the design time. Layout implementations, in 90 nm CMOS process, as well as the delay, energy and jitter electrical simulations are provided. http://hdl.handle.net/2117/15319 Title: Hypobaric chamber for wind sensor testing in Martian condictions Authors: Kowalski, Lukasz; García Molina, Francisco Miguel Abstract: In this paper we will describe the installation of a low pressure stainless steel horizontal chamber to be used in preliminary tests of a Mars atmosphere wind sensor. It includes custom made additional QF ports, electric and pneumatic interfaces together with a vacuum pump system. Absolute pressure, as a function of the pump operational time during the vacuum process and depressurization will be shown as a result of experimental measurements. We will propose the integration of a typical compact wind tunnel with interior of the vacuum chamber. We will also discuss the possibility of the reproduction the same Reynolds number conditions for a given low temperature of a pure carbon dioxide atmosphere just by fine adjustment of either air pressure or air velocity inside the chamber at typical laboratory temperature. Finally, we will recapitulate all pros and cons of this hypobaric chamber. Thu, 23 Feb 2012 09:23:05 GMT http://hdl.handle.net/2117/15319 2012-02-23T09:23:05Z Kowalski, Lukasz; García Molina, Francisco Miguel no In this paper we will describe the installation of a low pressure stainless steel horizontal chamber to be used in preliminary tests of a Mars atmosphere wind sensor. It includes custom made additional QF ports, electric and pneumatic interfaces together with a vacuum pump system. Absolute pressure, as a function of the pump operational time during the vacuum process and depressurization will be shown as a result of experimental measurements. We will propose the integration of a typical compact wind tunnel with interior of the vacuum chamber. We will also discuss the possibility of the reproduction the same Reynolds number conditions for a given low temperature of a pure carbon dioxide atmosphere just by fine adjustment of either air pressure or air velocity inside the chamber at typical laboratory temperature. Finally, we will recapitulate all pros and cons of this hypobaric chamber. http://hdl.handle.net/2117/14396 Title: Optimización de un Centro de Fusión CFAR para Sistemas Distribuidos RADAR Authors: Ortega Villasclaras, Pablo Rafael; Elias Fusté, Antonio Abstract: Distributed detection theory is widely used in surveillance systems that recquire a large area of coverage and a large number of targets under consideration. In this paper an optimization algorithm for distributed systems is described. The optimization criterion maximizes the probability of detection in the Data Fusion Center, keeping the overall probability of a false alarm constant. Furthermore the optimal decision rules in the Data Fusion Center are showed, in function of the sensor characteristics. Mon, 02 Jan 2012 19:03:50 GMT http://hdl.handle.net/2117/14396 2012-01-02T19:03:50Z Ortega Villasclaras, Pablo Rafael; Elias Fusté, Antonio no Distributed detection theory is widely used in surveillance systems that recquire a large area of coverage and a large number of targets under consideration. In this paper an optimization algorithm for distributed systems is described. The optimization criterion maximizes the probability of detection in the Data Fusion Center, keeping the overall probability of a false alarm constant. Furthermore the optimal decision rules in the Data Fusion Center are showed, in function of the sensor characteristics. http://hdl.handle.net/2117/14165 Title: A new design of high precision solar microsensor for satellite aplications Authors: Delgado, Francisco; Ortega Villasclaras, Pablo Rafael; Lopez Tarrida, Cristina; Garcia Ortega, Juan; Angulo, Manuel; Quero Reboul, Jose Manuel Abstract: This paper shows the design and calibration of an improved miniaturized two-axis sun sensor for satellite attitude control. The proposed new structure is based on a previous sun sensor structure by adding multiple sensing cells. The improvement in precision is obtained by the subdivision of field of view (FoV), which is expected to be ±60°, with a resolution of 0.1°. In the paper, both the mathematical model and the experimental results are presented. The resulting device will be incorporated in Microsat satellite from INTA, which will be launched in 2012. Fri, 02 Dec 2011 19:46:16 GMT http://hdl.handle.net/2117/14165 2011-12-02T19:46:16Z Delgado, Francisco; Ortega Villasclaras, Pablo Rafael; Lopez Tarrida, Cristina; Garcia Ortega, Juan; Angulo, Manuel; Quero Reboul, Jose Manuel no This paper shows the design and calibration of an improved miniaturized two-axis sun sensor for satellite attitude control. The proposed new structure is based on a previous sun sensor structure by adding multiple sensing cells. The improvement in precision is obtained by the subdivision of field of view (FoV), which is expected to be ±60°, with a resolution of 0.1°. In the paper, both the mathematical model and the experimental results are presented. The resulting device will be incorporated in Microsat satellite from INTA, which will be launched in 2012. http://hdl.handle.net/2117/13882 Title: Modeling and simulation of a cost-effective microfluidic circuit for particles' manipulation Authors: Virgilio, Vito di; Bermejo Broto, Sandra; Castañer Muñoz, Luis María; Coll Valenti, Aranu Mon, 14 Nov 2011 17:48:38 GMT http://hdl.handle.net/2117/13882 2011-11-14T17:48:38Z Virgilio, Vito di; Bermejo Broto, Sandra; Castañer Muñoz, Luis María; Coll Valenti, Aranu no http://hdl.handle.net/2117/13621 Title: Tendencias actuales en la energía solar fotovoltaica Authors: Prat Viñas, Lluís Fri, 21 Oct 2011 13:19:58 GMT http://hdl.handle.net/2117/13621 2011-10-21T13:19:58Z Prat Viñas, Lluís no sistemas fotovoltaicos http://hdl.handle.net/2117/13017 Title: Optimization of the rear point contact scheme of crystalline silicon solar cells using laser-fired contacts Authors: Molpeceres, C.; Perales Lorente, José Francisco; Ortega Villasclaras, Pablo Rafael; Orpella García, Alberto; López, Gema; Martín García, Isidro; Voz Sánchez, Cristóbal; Alcubilla González, Ramón; Sánchez, Isabel; Colina, M. Abstract: This paper is focused on the optimization of the rear contact scheme of p-type c-Si LFC-PERC high efficiency solar cells minimizing base ohmic losses without jeopardize rear passivation. This is carried out optimizing on one hand the LFC laser conditions for minimum point resistance and on the other hand through a proper design of the contact grid layout finding the optimum trade off for a given base resistivity between rear passivation and base resistance. LFC process was carried out through 110 nm thermal SiO2 passivation layer using IR and green lasers. Very low specific contact resistances, 0.1 mcm2 have been achieved independently of the laser used. For optimum rear contacted area fraction efficiencies over 21.5% and 22%, for IR and green lasers respectively are expected in the 0.5-5 cm resistivity range. Wed, 20 Jul 2011 17:17:59 GMT http://hdl.handle.net/2117/13017 2011-07-20T17:17:59Z Molpeceres, C.; Perales Lorente, José Francisco; Ortega Villasclaras, Pablo Rafael; Orpella García, Alberto; López, Gema; Martín García, Isidro; Voz Sánchez, Cristóbal; Alcubilla González, Ramón; Sánchez, Isabel; Colina, M. no This paper is focused on the optimization of the rear contact scheme of p-type c-Si LFC-PERC high efficiency solar cells minimizing base ohmic losses without jeopardize rear passivation. This is carried out optimizing on one hand the LFC laser conditions for minimum point resistance and on the other hand through a proper design of the contact grid layout finding the optimum trade off for a given base resistivity between rear passivation and base resistance. LFC process was carried out through 110 nm thermal SiO2 passivation layer using IR and green lasers. Very low specific contact resistances, 0.1 mcm2 have been achieved independently of the laser used. For optimum rear contacted area fraction efficiencies over 21.5% and 22%, for IR and green lasers respectively are expected in the 0.5-5 cm resistivity range.