Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV22)
DOI: https://doi.org/10.29363/nanoge.hopv.2022.032
Publication date: 20th April 2022
Classically, light absorption and electrical charge creation rely on gap materials, which create excitons upon absorption photons with sufficient energy to overcome the gap, resulting in the formation of electron-hole pairs. Consequently, photons with lower energy than the gap cannot create excitons, while the excess energy of photons with high energy is lost rapidly as heat. Plasmonic is a gapless material that absorb light via highly effective resonance process. If properly harnessed, it can be disruptive and transformative. Plasmonic absorb photons far beyond their cross-section (Poynting vector) [1], causing its electrons to resonate coherently with light electromagnetic field [2].Plasmon resonance decays non-radiatively via Landau damping, a purely quantum mechanical process. A plasmon quantum is transferred into a single electron-hole pair excitation on a timescale ranging from 1 to 100 fs [3]. The hot electrons generated from plasmon decay will quickly redistribute their energy among many lower-energy electrons via electron-electron scattering processes [4]. In 2013, my group provided the first evidence for hot-carrier formation upon plasmon excitation [5], catalysing the interest in direct hot carrier utilization. Hot carriers’ lifetime could be expedited by transferring them into suitable acceptors sequentially [6-9] or simultaneously [10] that is necessary to make a photovoltaic. Remarkably the plasmon carrier kinetic energy increased with medium temperature [11], antagonistic to other photovoltaic materials, opening the possibility for photovoltaics that operate at high temperature. In this lecture, I will present the plasmonic materials unique photophysical processes leading to electrical carriers’ generation and how we can harvest them. The approach is being used by us to produce highly transparent colourless solar cells for energy harvesting applications.
I would like to acknowledge all the authors that contributed to the work presented herein, and the financial support from Swedish Research Council, Swedish Energy Agency, Knut and Alice Wallenberg foundation and Vinnova.