Dissertation Talk: Engineering Tellurium - From Quantum Wires to Robust Transistors

Event details Date: Wednesday, July 29, 2026 Time: 9:30 AM to 9:30 AM Location: (in-person) Cory Hall Room 540AB Type: Film Audience: Faculty,Students About this event There is an ongoing push to develop back-end-of-line (BEOL)-compatible channel materials for integration with silicon electronics. While significant progress has been made on n-type BEOL-compatible channels, a promising p-type counterpart remains lacking. Tellurium, a one-dimensional van der Waals semiconductor of helical atomic chains, is highly promising for this role, yet its practical adoption has been held back by degradation at metal interfaces and by limited control over its crystallization. In this talk, I will show how engineering tellurium’s contacts and structure transforms it from a promising material into an integration-ready platform, progressing from wafer-compatible transistors down to the single-charge quantum limit. First, I will address the interface bottleneck: conventional contacts such as nickel and palladium interdiffuse into the tellurium channel at BEOL processing temperatures, degrading device performance. I will identify ruthenium as a thermally robust contact that resists interdiffusion up to 250 °C while delivering a low, Ohmic contact resistance of 1.25 kΩ·μm. Building on this, I will then introduce a templated synthesis approach that deterministically aligns single-crystal tellurium atomic chains on amorphous substrates, with strong alignment emerging for template widths below 20 nm. This structural control gives access to intrinsic one-dimensional transport phenomena inaccessible in thin films: quantized conductance plateaus from individual 1D subbands at 77 K, and Coulomb blockade at 1.7 K, where the wire behaves as a gate-tunable quantum dot supporting single-charge tunneling. Together, these results establish control of tellurium’s interfaces and dimensionality as the key to unlocking its potential across classical and quantum nanoelectronics. Official event details: https://events.berkeley.edu/eecs/event/324536-dissertation-talk-engineering-tellurium-from