You are cordially invited to the Ph.D. Thesis Defense Presentation
\n“Discovery of Low-Dimensional Solid-State Ionic Conductors”<\/p>\n
Amir Parsi, Ph.D. Student in Materials Science and Nanotechnology Graduate Program<\/p>\n
Abstract: Understanding intrinsic ion transport in solids is essential for developing next-generation energy, memory, and neuromorphic technologies. However, grain boundaries and structural disorder in conventional materials often obscure the underlying mechanisms. This dissertation addresses this challenge by investigating cation-driven phase transitions in low-dimensional single crystals. Using a custom-built real-time optical chemical vapor deposition (RTO-CVD) platform, four model systems\u2014AgI, Na-MnO2, KxWO3, and Cu2-xSe\u2014are studied to reveal how confined ionic motion enables reversible and tunable transformations.<\/p>\n
In this thesis, I demonstrate the growth of single-crystalline \u03b2-AgI nanoflakes exhibiting superionic conductivity and filamentary memristive switching driven by Ag+ migration. I further show that intrinsically Na+-intercalated \u03b4-MnO2 nanosheets display moisture-sensitive ionic transport and reversible structural transformations that enable neuromorphic behavior. Through studies of single-crystalline KxWO3 nanobelts, I reveal how electric-field-driven K+ redistribution within one-dimensional tunnels gives rise to bipolar resistive switching and analog conductance modulation. Finally, I investigate Cu2-xSe crystals, where liquid-like Cu+ mobility produces an ion-mediated insulator\u2013metal transition and contact-dependent photothermal responses linked to vacancy ordering and interfacial effects.<\/p>\n
Taken together, the results presented in this thesis provide experimental insight into ion-mediated transformations in low-dimensional materials and highlight the unique advantages of single-crystal platforms for studying intrinsic ionic processes. The findings establish a foundation for the design of future ionic and mixed ionic\u2013electronic devices, including solid-state memristors, neuromorphic systems, and reconfigurable optoelectronic technologies.<\/p>\n
Keywords: Solid-State Ionics, Real-Time Optical Chemical Vapor Deposition (RTO-CVD), Single-Crystalline AgI Nanoflakes, Intrinsically Intercalated Na\u2013MnO2 Nanosheets, Single-Crystalline KxWO3 Nanobelts, Cu2-xSe Mixed Ionic\u2013Electronic Conductor<\/p>\n
Supervisor: Dr. Aykut Erba\u015f
\nCo-Supervisor: Dr. T. Serkan Kas\u0131rga
\nDate: Thursday, June 25, 2026
\nTime: 13:00
\nThis is an online seminar. To request event details please send a message to department.<\/p>\n","protected":false},"excerpt":{"rendered":"
You are cordially invited to the Ph.D. Thesis Defense Presentation “Discovery of Low-Dimensional Solid-State Ionic Conductors” Amir Parsi, Ph.D. Student in Materials Science and Nanotechnology Graduate Program Abstract: Understanding intrinsic ion transport in solids is essential for developing next-generation energy, memory, and neuromorphic technologies. However, grain boundaries and structural disorder [\u2026] <\/p>\n