Memorias de investigación
Communications at congresses:
A puzzling solar cell structure: an exercise to get insight on intermediate band solar cells
Year:2013

Research Areas
  • Solar cells

Information
Abstract
We introduce one trivial but puzzling solar cell structure. It consists of a high bandgap pn junction (top cell) grown on a substrate of lower bandgap. Let us assume, for example, that the bandgap of the top cell is 1.85 eV (Al 0.3Ga 0.7As) and the bandgap of the substrate is 1.42 eV (GaAs). Is the open-circuit of the top cell limited to 1.42 V or to 1.85 V? If the answer is ldquo1.85 Vrdquo we could then make the mind experiment in which we illuminate the cell with 1.5 eV photons (notice these photons would only be absorbed in the substrate). If we admit that these photons can generate photocurrent, then because we have also admitted that the voltage is limited to 1.85 V, it might be possible that the electron-hole pairs generated by these photons were extracted at 1.6 V for example. However, if we do so, the principles of thermodynamics could be violated because we would be extracting more energy from the photon than the energy it initially had. How can we then solve this puzzle?
International
Si
Congress
39th IEEE Photovoltaic Specialists Conference
960
Place
Tampa, FL, USA
Reviewers
Si
ISBN/ISSN
978-1-4799-3299-3
Start Date
16/06/2013
End Date
21/06/2013
From page
1069
To page
1073
Proceedings 39th IEEE PVSC
Participants

Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Silicio y Nuevos Conceptos para Células Solares
  • Centro o Instituto I+D+i: Instituto de Energía Solar
  • Departamento: Electrónica Física