Strategies for high-performance solid-state photon up-conversion based on triplet exciton annihilation
Tuesday, October 27 at 11 a.m. EDT
Ting-An Lin, PhD candidate
Electrical Engineering & Computer Science (EECS)
Photon up-conversion, a non-linear optical process to convert low-energy photons into higher energies, has various applications such as photovoltaics, infrared sensing, and bio-imaging. Particularly, up-conversion based on triplet exciton annihilation is one of the most promising approaches to achieve high efficiency at low excitation intensity for practical applications. However, the reported performance in solid-state is limited due to energy back transfer, material aggregation, and weak optical absorption, which complicates the integration with solid-state applications.
In this talk, Lin will discuss the research group's proposed strategies to improve the performance in solid-state. In a green-to-blue up-converter consisting of a bilayer of an absorbing and an up-converting material, they reduced energy back transfer by inserting a blocking layer in between and mitigate aggregation by doping the absorber into a host material. The up-conversion efficiency had a 7-fold enhancement with the excitation intensity reduced by 9 times. To improve optical absorption, they investigated an infrared-to-visible up-converter and integrate the up-converting layers into a Fabry-Pérot microcavity. At the resonant wavelength, absorption increases 74-fold and the threshold excitation intensity is reduced by two orders of magnitude to a sub-solar flux. Their work demonstrates the importance of device structure engineering to improve the performance of solid-state photon up-conversion, and offers a path toward practical applications.
Attendees can join and participate in the series via Zoom. Meeting ID#: 860 986 455.