UCLA

Chem 248 Organic Chemistry Student Seminar: James Collings
2025-11-03 15:00 - 16:00 (America/Los_Angeles) | Collaboratory Yoo Seminar & Conference Hall YH4222

Physical Chemistry Seminar 228: Prof. Sergio Carbajo
2025-11-03 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Jeffrey I. Zink Inorganic Chemistry Seminar Series – Prof. Jun Ohata
2025-11-05 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Chem 218 Student Exit Talk: Diego Garcia Vidales
2025-11-06 12:00 - 13:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
Conjugated polymers are electronic materials that combine semiconductor-like behavior with mechanical flexibility, solution processability, and chemical tunability. However, their intrinsically low carrier density and heterogeneous microstructure pose challenges for efficient charge transport. To mitigate the low carrier density, we incorporate carriers via chemical doping into semiconducting polymer thin films. This talk investigates how chemical doping and polymer morphology jointly dictate charge transport across molecular, mesoscale, and macroscopic length scales, with implications for electronic and thermoelectric applications. We characterize the doped films using techniques such as four-point probe conductivity, Seebeck coefficient measurements, Hall effect measurements, X-ray scattering, and spectroscopy. We first study how the hygroscopicity of the counterions in doped polymer thin films can significantly influence electronic transport by enabling water uptake. We show that absorbed moisture introduces trap states and suppresses carrier mobility, underscoring the need to consider environmental stability and dopant chemistry when chemically doping polymer devices. Second, we dope the same polymer with four molecular dopants and find that the choice of dopant affects not only carrier generation but also structural ordering, crystallite connectivity, and Coulomb trapping, leading to distinct charge-transport pathways and thermoelectric performance. Importantly, we show that electrical conduction can be enhanced without sacrificing Seebeck coefficient either by mitigating Coulomb interactions or by activating charge transport through previously amorphous regions. Finally, we isolate the role of the polymer microstructure by tuning the polymer crystallinity by controlling regioregularity. We find that higher intrinsic crystallinity promotes greater polaron delocalization and faster local transport, and that dopant- induced crystallization in amorphous regions can enhance mesoscale connectivity. The combination of high local order and doping-enabled long-range connectivity is essential for maximizing mobility and thermoelectric performance. Overall, this work establishes structure–doping–transport relationships in doped conjugated polymers and highlights design principles for next-generation polymer conductors: choose dopants that both minimize trapping and enable structural reinforcement, and engineer polymer microstructure to balance local order and mesoscale connectivity.

Houk-Jung Organic Colloquium 247 - Prof. Colleen Scott
2025-11-06 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Dickerson Biochemistry Chemistry Seminar 268: Prof. Michael Lawson and Prof. Antonio Tinoco Valencia
2025-11-07 15:30 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Chem 248 Organic Chemistry Student Seminar: Hang Chi Ho
2025-11-10 15:00 - 16:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Physical Chemistry Seminar 228: Carl Percival
2025-11-10 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Houk-Jung Organic Colloquium 247 - Prof. Darci Trader
2025-11-13 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Dickerson Biochemistry Chemistry Seminar 268: Prof. Jose Rodriguez and Prof. Kalli Kappel
2025-11-14 15:30 - 17:00 | CA

Jeffrey I. Zink Inorganic Chemistry Seminar Series – Prof. Arie Borenstein
2025-11-17 11:00 - 12:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Chem 248 Organic Chemistry Student Seminar: Max Lyons
2025-11-17 14:00 - 15:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Physical Chemistry Seminar 228: Prof. Milan Delor
2025-11-17 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Jeffrey I. Zink Inorganic Chemistry Seminar Series – Prof. Christopher Hendon
2025-11-19 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Bristol-Myer Squibb Lectureship - Dr. Thomas Cummins | Prof. Ian Seiple
2025-11-20 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Dickerson Biochemistry Chemistry Seminar 268: Prof. David Eisenberg and Prof. Steffen Lindert
2025-11-21 15:30 - 17:00 | CA

Chem 248 Organic Chemistry Student Seminar: Marianna Tonoyan
2025-11-24 15:00 - 16:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Physical Chemistry Seminar 228: Manabu Shiraiwa
2025-11-24 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Jeffrey I. Zink Inorganic Chemistry Seminar Series – Prof. Ricardo Louro
2025-11-26 11:00 - 12:15 | Collaboratory Yoo Seminar & Conference Hall YH4222

Chem 248 Organic Chemistry Student Seminar: Zuwei Wang
2025-12-01 15:00 - 16:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Physical Chemistry Seminar 228: Prof. John Anderson
2025-12-01 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Jeffrey I. Zink Inorganic Chemistry Seminar Series – Prof. Karen Goldberg
2025-12-03 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Dickerson Biochemistry Chemistry Seminar 268: Prof. Hong Zhou and Prof. Robert Clubb
2025-12-05 15:30 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Winter Holiday Celebration
2025-12-08 15:30 - 18:30 | Hershey Hall, 801 Hilgard Ave, Los Angeles, CA, 90095, United States

Chem 248 Organic Chemistry Student Seminar: Yan Liu
2026-01-05 15:00 - 16:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Physical Chemistry Seminar 228: Prof. Ni Ni
2026-01-05 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Jeffrey I. Zink Inorganic Chemistry Seminar Series – Prof. R. David Britt
2026-01-07 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Jeffrey I. Zink Inorganic Chemistry Seminar Series – Prof. Takhee Lee
2026-01-08 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Dickerson Biochemistry Seminar Series 268 – Prof. Siyuan (Steven) Wang
2026-01-09 15:30 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Chem 248 Organic Chemistry Student Seminar: Cesar Torres
2026-01-12 15:00 - 16:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
