Development of new solutions for solar energy conversion

Development of new solutions for solar energy conversion

Description of the activity

The high vacuum flat solar thermal collectors open new opportunities for the production on clean energy with high efficiency. We design new Selective Solar Absorbers (SSA), based on multilayer architecture, to increase the energy conversion efficiency at temperature higher than 150°C. The layer materials are deposited by e-beam evaporation and magnetron sputtering and their optical properties studied by ellipsometry to obtain their complex refractive index. The SSA can be optimized for different working temperatures and the coating efficiency can be higher than 0.6 at 300°C.
The material optical properties can be tuned adjusting the deposition conditions.
The deposited materials can be used to fabricate Selective absorber as well as Infrared mirrors to improve efficiency through photon recycling. They can be measured by standard optical techniques and/or by our custom calorimetric system newly refurbished with a calibrated LED illumination device.
Other routes will be investigated to further improve the solar energy conversion efficiency such as the hybrid photovoltaic for thermal and electrical energy generation, low emissivity coatings to further reduce the thermal losses of the SSA as well as the substrate.
The new methods to assess the thermal stability and service lifetime of produced selective coatings are also under study.

Involved personnel

R. Russo | M. Casalino | M. Iodice | M.A. Gioffrè | D. De Luca | A. Caldarelli | E. Gaudino | U. Farooq

National and International Collaborations


  • Clean-room: e-beam evaporation, magnetron sputtering (DC and RF), thermal oxidation, wet etching, profilometry;
  • Optical characterization: Integrating sphere, FTIR, OSA, ellissometry.

Active projects and contracts

  • Highly Efficient Solar Steam Generation for Industrial Process Heat, project ESSTEAM number E!115642, EUREKA Eurostar program, 2021-2024 .Responsible: R. Russo.
  • Research contract TRESOL-CNR: “R&D on multilayers for evacuated solar thermal flat panel” Responsible: R. Russo.