Search query: physics of solar cells würfel

Related papers:

abstract: 1 Problems of the Energy Economy 2 Photons 3 Semiconductors 4 Conversion of Thermal Radiation into Chemical Energy 5 Conversion of Chemical Energy into Electrical Energy 6 Basic Structure of Solar Cells 7 Limitations on Energy Conversion in Solar Cells 8 Concepts for Improving the Efficiency of Solar Cells 9 Prospects for the Future
author_names: Peter Prof Dr Wurfel

Uli Wurfel
title: Physics of solar cells from basic principles to advanced concepts
year: 2009

abstract: List of Symbols.Preface.1 Problems of the Energy Economy.1.1 Energy economy.1.2 Estimate of the maximum reserves of fossil energy.1.3 The greenhouse effect.2 Photons.2.1 Black body radiation.2.2 Kirchhoff's law of radiation for non black bodies.2.3 The solar spectrum.2.4 Concentration of the solar radiation.2.5 Maximum efficiency of solar energy conversion.3 Semiconductors.3.1 Electrons in semiconductors.3.2 Holes.3.3 Doping.3.4 Quasi Fermi distributions.3.5 Generation of electrons and holes.3.6 Recombination of electrons and holes.3.7 Light emission by semiconductors.4 Conversion of Thermal Radiation into Chemical Energy.4.1 Maximum efficiency for the production of chemical energy.5 Conversion of Chemical Energy into Electrical Energy.5.1 Transport of electrons and holes.5.2 Separation of electrons and holes.5.3 Diffusion length of minority carriers.5.4 Dielectric relaxation.5.5 Ambipolar diffusion.5.6 Dember effect.5.7 Mathematical description.6 Basic Structure of Solar Cells.6.1 A chemical solar cell.6.2 Basic mechanisms in solar cells.6.3 Dye solar cell.6.4 The pn junction.6.5 pn junction with impurity recombination, two diode model.6.6 Hetero junctions.6.7 Semiconductor metal contact.6.8 The role of the electric field in solar cells.7 Limitations on Energy Conversion in Solar Cells.7.1 Maximum efficiency of solar cells.7.2 Efficiency of solar cells as a function of their energy gap.7.3 The optimal silicon solar cell.7.4 Thin film solar cells.7.5 Equivalent circuit.7.6 Temperature dependence of the open circuit voltage.7.7 Intensity dependence of the efficiency.7.8 Efficiencies of the individual energy conversion processes.8 Concepts for Improving the Efficiency of Solar Cells.8.1 Tandem cells.8.2 Concentrator cells.8.3 Thermo photovoltaic energy conversion.8.4 Impact ionization.8.5 Two step excitation in three level systems.9 Prospects for the Future.Appendix.Index.
author_names: Peter Prof Dr Wurfel
title: Physics of solar cells from principles to new concepts
year: 2005

author_names: Peter Prof Dr Wurfel
title: Physics of solar cells
year: 2005

abstract: The selective transport of electrons and holes to the two terminals of a solar cell is often attributed to an electric field, although well known physics states that they are driven by gradients of quasi Fermi energies. However, in an illuminated semiconductor, these forces are not selective, and they drive both charge carriers toward both contacts. This paper shows that the necessary selectivity is achieved by differences in the conductivities of electrons and holes in two distinct regions of the device, which, for one charge carrier, allows transport to one contact and block transport to the other contact.
author_names: Uli Wurfel

Andres Cuevas

Peter Wurfel
title: Charge Carrier Separation in Solar Cells
venue: IEEE Journal of Photovoltaics
year: 2015

abstract: Solar cells may become the most important option for the energy supply of mankind. It would certainly help if their efficiency could be raised substantially above the present value for commercial panels of 12 to 15% General thermodynamical arguments give much higher efficiency limits. In order to exploit them with solar cells, future concepts should be based only on necessary requirements. Present day solar cells are based on pn junctions and their understanding goes back to the beginnings of semiconductor device physics [1] It will be shown that pn junctions do not really belong to the necessary requirements. In addition, their understanding is at least misleading when applied to solar cells. In order to be able to find new concepts for more efficient solar cells, wrong ideas must be corrected. Since thermodynamics is independent of particular device aspects, it is particularly well suited to explore the limits of solar cells.
author_names: Peter Prof Dr Wurfel
title: Thermodynamics of Solar Cells
year: 2004

author_names: Ghassan E Jabbour

Evan Laurence Williams
title: Book Review: Physics of Solar Cells. By Peter Wurfel.
year: 2005

abstract: Books reviewed: Physics of Solar Cells, 2nd Edition (Wurfel, P. 2009) Essentials of RF and Microwave Grounding (Holtzman, E. 2006) Polymer Tribology (Sinha, S. K. and Briscoe,B. J. 2009) PVC Degradation and Stabilization (Wypych, G. 2008) Advanced Batteries (Huggins, R. A. 2009) The Lineman's and Cableman's Field Manual, 2nd Edition (Shoemaker, T. M. and Mack, J. E. 2009) Lead Your Boss (Baldoni, J. 2009) Industrial Power Systems (Khan, S. 2008)
author_names: John J Shea
title: Book reviews [8 books reviewed]
venue: IEEE Electrical Insulation Magazine
year: 2010

abstract: Abstract Following the recent success of monolithically integrated Perovskite/Si tandem solar cells, great interest has been raised in searching for alternative wide bandgap top cell materials with prospects of a fully earth abundant, stable and efficient tandem solar cell. Thin film chalcogenides (TFCs) such as the Cu 2 ZnSnS 4 (CZTS) could be suitable top cell materials. However, TFCs have the disadvantage that generally at least one high temperature step 500 degC) is needed during the synthesis, which could contaminate the Si bottom cell. Here, we systematically investigate the monolithic integration of CZTS on a Si bottom solar cell. A thermally resilient double sided Tunnel Oxide Passivated Contact (TOPCon) structure is used as bottom cell. A thin 25 nm) TiN layer between the top and bottom cells, doubles as diffusion barrier and recombination layer. We show that TiN successfully mitigates in diffusion of CZTS elements into the c Si bulk during the high temperature sulfurization process, and find no evidence of electrically active deep Si bulk defects in samples protected by just 10 nm TiN. Post process minority carrier lifetime in Si exceeded 1.5 ms, i.e. a promising implied open circuit voltage (i V oc of 715 mV after the high temperature sulfurization. Based on these results, we demonstrate a first proof of concept two terminal CZTS/Si tandem device with an efficiency of 1.1% and a V oc of 900 mV. A general implication of this study is that the growth of complex semiconductors on Si using high temperature steps is technically feasible, and can potentially lead to efficient monolithically integrated two terminal tandem solar cells.
author_names: Alireza Hajijafarassar

Filipe Martinho

Fredrik Stulen

Sigbjorn Grini

Sim'on L'opez-Marino

Moises Esp'indola-Rodr'iguez

Max Dobeli

Stela Canulescu

Eugen Stamate

Mungunshagai Gansukh

Sara Engberg

Andrea Crovetto

Lasse Vines

J Schou

Ole Hansen Dtu Nanolab

Technical University of Denmark

Department of Electrical Engineering

Technical Physics

University of Oslo Ion Beam Physics

Eth Zurich Dtu Physics
title: Monolithic thin film chalcogenide silicon tandem solar cells enabled by a diffusion barrier
year: 2019

abstract: The presence of interface recombination in a complex multilayered thin film solar structure causes a disparity between the internal open circuit voltage (VOC,in) measured by photoluminescence, and the external open circuit voltage (VOC,ex) i.e. an additional VOC deficit. Higher VOC,ex value aim require a comprehensive understanding of connection between VOC deficit and interface recombination. Here, a deep near surface defect model at the absorber/buffer interface is developed for copper indium di selenide solar cells grown under Cu excess conditions to explain the disparity between VOC,in and VOC,ex. The model is based on experimental analysis of
author_names: Mohit Sood

Aleksander Urbaniak

Christian Kameni Boumenou

Thomas Paul Weiss

Hossam Elanzeery

Finn Babbe

Florian Werner

Michele Melchiorre

Susanne Siebentritt Department of Physics

Materials Science

University of Luxembourg

Luxembourg Faculty of Physics

Warsaw University of Technology

79 Koszykowa

Warszawa 00-662

Poland Chemical Sciences Division

Joint Center for Artificial Photosynthesis

Lawrence Berkeley National Laboratory

Usa Hydrosat

rue du Laboratoire

L-1911 Luxembourg
title: Near surface defects: Cause of deficit between internal and external open circuit voltage in solar cells
year: 2021

abstract: Empirical data for the fill factor as a function of charge carrier mobility for two different polymer:fullerene systems is presented and analyzed. The results indicate that charge extraction depth limitations and space charge effects are inconsistent with the observed behavior, and the decrease in the fill factor is, instead, attributed to the field dependent charge separation and geminate recombination. A solar cell photocurrent limited by the Onsager Braun charge transfer exciton dissociation is shown to be able to accommodate the experimental observations. Charge dissociation limited solar cells always benefit from increased mobilities, and the negative contribution from the reduced charge separation is shown to be much more important for the fill factor in these material systems than any adverse effects from charge carrier extraction depth limitations or space charge effects due to unbalanced mobilities. The logarithmic dependence of the fill factor on the mobility for such a process is also shown to imply that simply increasing the mobilities is an impractical way to reach very high fill factors under these conditions since unrealistically high mobilities are required. A more controlled morphology is, instead, argued to be necessary for high performance. V C 2011 American Institute of Physics. [doi:10.1063/1.3609079]
author_names: Lars Mattias Andersson

Christian Muller

Bekele H Badada

Fengling Zhang

Uli Wurfel

Olle Inganas
title: Mobility and fill factor correlation in geminate recombination limited solar cells
year: 2011