About the Speaker:

Prof. Young grew up in eastern Pennsylvania. She attended Haverford College as an undergraduate where she majored in Chemistry and minored in German, while also playing intercollegiate soccer and squash. As an undergraduate researcher, she worked in with Prof. Julio de Paula on porphyrin-peptide nano-wires – during which time her love of photochemistry and spectroscopy was ignited.  After completing her undergraduate studies, she spent a year abroad in Germany as a participant in the Congress-Bundestag Youth Exchange for Young Professionals. While in Germany, she learned about the German culture and language while working in the biophysical laboratory of Prof. Dr. Joachim Spatz at the University of Heidelberg. Upon returning to the U.S., she attended graduate school at the Massachusetts Institute of Technology earning a Ph.D. in Physical Chemistry. Her work in the laboratory of Prof. Daniel G. Nocera focused on photo-induced charge transfer coupled to proton motions in small-molecule donor-acceptor systems. She then spent two years as an NSF ACC-F post-doctoral fellow in the electrical engineering laboratory of Prof. Vladimir Bulovic at MIT learning about charge transfer in organic semiconductor devices.

In 2011, Prof Young began her independent career working with undergraduate students at Amherst College. She moved back to Pennsylvania in 2017 to Lehigh University where she is currently an Assistant Professor. Prof Young’s research efforts focus on understanding excited-state charge transfer processes for a range of applications, including excited-state proton-coupled electron transfer reactions in model system and photo-induced charge transfer in materials of interest for next generation photovoltaic devices.

To learn more, check the Young Research Group website.

About the Seminar:

Title:

From Photodynamic Therapy to Photovoltaics: Photophysics of Pd(II)biladiene and Charge Carrier Dynamics in Thin Films of Light Harvesting Sb 2 S 3

Abstract:

Solar light harvesting and interconversion of solar energy into either electricity or driving force for small molecule activation reactions are critical to the production of energy and other processes that our society requires to function. In this talk, I will discuss two project united by photochemistry, each with their own application. In the first vignette, I will discuss a porphyrinoid complex, called a Pd(II)biladiene, This Pd(II)biladiene moiety was designed for use as a photosensitizer drug for photodynamic therapy. Up until this point, the excited-state dynamics of such biladiene complexes have been virtually unexplored. During our work on this moiety, we discovered that while excitation into the lowest-energy absorption feature of the Pd(II)biladiene complexes produces expected photophysics, interestingly, excitation into higher-lying excited states resulted in an additional, unexpected lifetime. I will discuss our work to propose the cause of this unexpected behavior. In the second vignette, I will discuss our recent work on stibnite (Sb 2 S 3 ), which can be employed as the photoactive layer in next generation thin-film solar cells. Sb 2 S 3 is of particular interest due to the suitable band gap of 1.7 eV and high absorption coefficient (1.8 × 10 5  cm –1 at 450 nm). I will present our work using transient absorption spectroscopy to directly observe carrier diffusion, electron transfer, hole transfer and charge recombination through uniform ultra-thin (< 3 nm) layers of insulating or transport materials deposited by atomic layer deposition (ALD) that are coupled to photo-active materials. Our results will be used to correlate the structure and function of material thickness and transport type to develop a fundamental, detailed, quantitative understanding of photo-induced ET dynamics through thin films of materials.