NanoTechnology: Materials, Processes & Devices

Surface tension plays an important role in miniaturized systems as the scaling law favors its relative significance over other forces such as gravity, magnetic, and structural stiffness. As such, surface tension effects have induced process issues in microfabrication such as stiction but also provided opportunities in using the surface tension to drive microdevices, such as those based on electrowetting-on-dielectric (EWOD), electrocapillary, and continuous electrowetting (CEW) mechanism, … etc. In this project, we exploit the giant outputs by the switching of surface tension...

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, we are modifying the sensor surface by applying thin hydrophobic layers, such as hexamethyldisilazane (HMDS), to achieve ultrahydrophobicity,...

Black phosphorus (BP) is a promising material for optoelectronic applications due to its direct bandgap at all thicknesses, and low Auger recombination coefficient at high carrier densities. BP, being a two-dimensional material, lacks scalability, for which techniques for its large-area processing are important. In this work, we find methodologies to utilize this material for large-scale optoelectronic applications.

Project currently funded by: Federal

Black phosphorus has emerged as a unique optoelectronic material, exhibiting tunable and high device performance from mid-infrared to visible wavelengths. Understanding the photophysics of this system is of interest to further advance device technologies based on it. Here we report the thickness dependence of the photoluminescence quantum yield at room temperature in black phosphorus while measuring the various radiative and non-radiative recombination rates. As the thickness decreases from bulk to ~4 nm, a drop in the photoluminescence quantum yield is initially observed due to enhanced...