STW grant for UvA physicists Gregorkiewicz and Sinke
UvA professors Tom Gregorkiewicz (Institute of Physics, IoP) and Wim Sinke (IoP and Energy Research Centre for the Netherlands, ECN) have received a grant in the Open Technology programme of the Dutch Technology Foundation STW with their proposal "Towards photovoltaics of the future: using hot carriers to harvest energy of the entire solar spectrum".
Larger fraction of the solar light
The granted project aims to study “efficiency boosters” for solar cells and modules. The efficiency of all commercially available solar modules is strongly limited by the fact that they can only convert half of the energy in the broad solar spectrum at best. The energy of short wavelength (“blue”) photons can only be utilized partially, while long wavelength (“red”) photons are not absorbed at all, so that their energy is lost entirely. This sets the energy conversion efficiency limit at 25∼30% - the Shockley-Queisser limit. In the proposed solution, photons of all energies are absorbed in a system containing quantum dots by a combination of interband and intraband electronic transitions. Their energy is converted into (the excess energy of) hot electrons, i.e. electrons with energies well above the band edge. This excess energy is then transferred to emitters in the vicinity of the quantum dots, which subsequently release photons of a single wavelength. When these are absorbed, they can be converted to electrical energy very efficiently (in principle at ≈ 60%) in a standard solar cell.
As with all STW projects, the proposal contains a clear utilisation paragraph and collaborations with industry: ECN (Petten), SunEdison Semiconductor / MEMC Electronic Materials (Italy), NXP, as well as some smaller industrial partners.
The grant allows the team to hire two PhD students and two postdocs. In addition, it contains a material budget for investments in lab equipment.
The project fits well with the Solardam consortium, the joint Solar Energy research initiative for the Amsterdam region, and will contribute to its research programme. Solardam was started a few years ago by group leaders from UvA, VU, FOM Institute AMOLF and ECN. It was recently awarded with seed money funding from the Amsterdam Academic Alliance (AAA). Both PIs are active and founding members of the Solardam consortium.