NanoTechnology: Materials, Processes & Devices

Chemiresistive gas sensors based on semiconductor metal oxides, such as tin dioxide, help to identify and monitor toxic gases and pollution, and play a vital role in industrial and environmental applications. However, the interfering effect of ambient humidity is a major challenge in their reliable operation, as water molecules on the oxide surface can affect the sensitivity and other characteristics of the sensor. To address this challenge, several surface modifications are being explored in this project. In one approach, we are utilizing atomic layer deposition (ALD),...

Using electroluminescence as a metrology method could have many advantages for on-chip characterization of chemical composition, where the need for an on-chip light source can be eliminated and materials with different excitation energies can be characterized by the same device. However, the range of materials that can be used in electroluminescent devices is typically limited due to challenges related to material processing and band alignment. In this project, we aim to develop a multiplexed electroluminescent device that can produce electroluminescence from infrared to ultraviolet...

State-of-the-art quantum computers currently have qubit gate error rates that are too large for practical computing. Quantum error correction can protect computations from physical errors by encoding logical qubits in many physical qubits. However, physical qubit error rates need to be sufficiently low to minimize resource overhead and suppress errors. As a result, compact qubit designs with small dissipation and error rates are crucial to scaling up a fault-tolerant quantum computer. In this project, we aim to address the scaling up of superconducting quantum processors by...

Despite decades of study and deployment, chemiresistive gas sensors based on SnO2 suffer from baseline drift due to aging of the SnO2 sensing material. In this work, we investigate how repeated, simulated operation of SnO2-based sensors causes irreversible changes in the electronic sensing behavior of SnO2, quantified through the bulk and inter-grain resistance of SnO2 as measured by potentiometric impedance spectroscopy (PIS). In tandem, we apply powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) to link the observed changes in the bulk and inter-grain...