(209d) Interfacial Engineering for Triplet Exciton Sensitization of Silicon Photovoltaics
AIChE Annual Meeting
2023
2023 AIChE Annual Meeting
Materials Engineering and Sciences Division
Electronic and Photonic Materials: Graduate Student Awards
Tuesday, November 7, 2023 - 8:42am to 8:56am
Recent work has shown coupling between Si and the archetype SF material tetracene (Tc) in the presence of passivating interfacial layers of Hafnium oxynitride [1]. Excitation spectra show a boost in the photoluminescence from Si when Tc is photoexcited that may be caused by energy transfer or changes in the silicon passivation [1]. To experimentally distinguish between these phenomena and understand the complex dynamics of excited states and charges at Si/Tc interfaces, we have developed a spectroscopy technique that is robust to the weak and intensity-dependent photoluminescence from silicon. Using combinations of biasing optical pumps and selective modulation of SF rates using a magnetic field, we study structural variations at the interface to probe the mechanism of coupling at Hafnium oxynitride interfaces and other rationally-designed heterostructures. We demonstrate positive contributions from tetracene to silicon photoluminescence that suggest a key role for charge transfer states in realizing solar cell efficiency enhancements from singlet exciton fission. Additionally, a better understanding of the molecule-semiconductor interface will translate to significant implications for other high efficiency optoelectronic devices beyond photovoltaics.
[1] Einzinger, M., Wu, T., Kompalla, J.F. et al. Sensitization of silicon by singlet exciton fission in tetracene. Nature 571, 90â94 (2019).