Universidad Politécnica de Madrid

Instituto de energía solar

R&D at IES

Silicon and New Solar Cell Concepts (SNSCC)



We are a team of around 20 researchers and technicians.  We are integrated, along with four other PV research groups, in the Instituto de Energía Solar (Solar Energy Institute) of the Universidad Politécnica de Madrid (Madrid Technical University), which is located at the campus of the School of Telecommunications Engineering, in the Ciudad Universitaria, in Madrid.

Our work

Our research group aims to support the development of photovoltaic energy through the reduction of costs and the increment of efficiency through different approaches, both in consolidated as in novel technologies. This activity is articulated through the following lines of research:


  • Intermediate band materials and solar cells
  • Quantum mechanical calculations
  • Nanostructures
  • Molecular beam epitaxy
  • Advanced characterization tools and device processing
  • Light management
  • Modelling and other novel solar cell concepts
  • Three terminal heterojunction bipolar transistor solar cells
  • Energy Storage: Novel system based on molten silicon latent heat
  • Solar silicon refinement
  • Defect engineering in solar silicon
  • Crystalline silicon solar cell development
Activity and other data of interest

Our daily activity focuses on providing the PV community with novel ideas letting spread out the use of solar energy. Thus, on one hand, we deal with the study of the limits for the conversion of solar light into photovoltaic energy, with special emphasis on new concepts that can dramatically improve the current performance of this conversion. Hence, the simulation tools, the technologic capacities and the characterization equipment and techniques we have available are elemental resources to foster the research lines in this area. The majority of these resources are accessible to third parties through the technological services offered by IBLAB (Laboratory of materials characterization and new generation solar cells) certified under the ISO9001 standard.

On the other hand, the group also addresses the research on the next generation of crystalline silicon solar cells, aiming at combining low cost and high efficiency. We adopt an integral approach that includes the production of solar silicon, the minimization of the impact of defects in device performance, and the research in promising solar cell structures, including the integration of silicon in a tandem structure with other semiconductors to surpass the practical efficiency limit of single junction solar cells.

Moreover, a research line on energy storage has also started in order to explore radically new combinations of solar cells, silicon and thermophotovoltaics to achieve high energy density storage systems based on molten silicon. This technology (SILSTORE) has attracted the interest and recognition of several bodies in order to promote the implementation of this breaking idea.

Our research activity has been endorsed by more than fifty research projects, of which more than half are framed in an international cooperation. We have coordinated several of them, of which we highlight the FULLSPECTRUM (FP6) project selected by the European Commission (EC) as one of the top 40 projects of the 6th Framework Programme. Other recent European projects we have been/are involved with are NGCPV (FP7 EU-NEDO), IBPOWER (FP7), CHEETAH (FP7) and AMADEUS (H2020).


Head of SNSCC Group: Prof. Antonio Martí

Keywords: silicon solar cells | ultrapurification | intermediate band solar cells | MBE, Molecular Beam epitaxy | IBLAB | energy storage | novel concepts.