Ali Javey (Advisor)

Research Advised by Professor Ali Javey

Javey Group:  List of Projects | List of Researchers

Hyong Min Kim

Graduate Student Researcher
Electrical Engineering and Computer Sciences
Professor Ali Javey (Advisor)
Ph.D. 2028 (Anticipated)

Hyong is a Ph.D. student in the Electrical Engineering and Computer Sciences Department at University of California, Berkeley. He received his Bachelor's Degree in Electrical Engineering from the Univeristy of Pennsylvania in 2023. In his undergraduate research, Hyong studied quantum emission from strained 2D materials, ferroelectric field-emission transistors based on AlScN/2D material heterostructures, and scanning probe characterization of 1D-2D material interfaces. Hyong's current research at Berkeley is on fabricating next-generation Mid-Wave Infrared (MWIR) optoelectronic devices...

BPN999: Wearable Sweat Sensors with High-Throughput Fabrication

Noelle Davis
Yullim Lee
Nicole Qing
Seung-Rok Kim
2024

We have been developing sweat sensors to analyze physiological and metabolic health information, such as sweat rate, glucose levels, pH, and various electrolytes, from any surface on the body surface where sweat glands are present. However, the stiff sweat sensors developed so far struggle to detect subtle signal changes, especially on soft skin. This is due to a mechanical mismatch between the rigid sweat sensor and the pliable skin, which can lead to motion artifacts and delamination of the patch from skin. Specifically, the stiff sensor cannot easily stretch along with the...

BPN984: Large-Area Processable Luminescent Black Phosphorus

Naoki Higashitarumizu
Hyong Min Kim
Theodorus Jonathan Wijaya
Shu Wang
Kyuho Lee
2024

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

BPN988: Modulation of Optoelectronics in Quantum Dot Film

I K M Reaz Rahman
Naoki Higashitarumizu
2023

Core/shell quantum dots are known to have high photoluminescence quantum yield for their passivation through thicker shell by suppressing surface trap states. In spite of their excellent exciton dynamics, these bright quantum dots tend to suffer from stability issues and degradation over time. Here we investigate their photo-physical properties due to charge injection, which leads to unfavorable recombination pathways through charged excitons. This provides an additional tuning knob for modulation of their photoluminescence quantum yield after synthesis, thereby offering a means of...

BPN971: High-Efficiency Ink-Based Mid-IR LEDs and Photodetectors

Theodorus Jonathan Wijaya
Hyong Kim
Naoki Higashitarumizu
Shu Wang
Kyuho Lee
2024

Midwave infrared (MWIR) is significant for applications such as sensing, imaging, and spectroscopy. Traditional materials in this wavelength range, III-V and II-VI semiconductors, has poor performance due to their high Auger recombination rate and large dark currents. Due to the better properties of black phosphorus (BP) such as its low Auger recombination coefficient, BP-based mid-infrared light emitters and detectors have shown to outperform the state-of-the-art commercial devices. However, the scalability of these devices remains questionable because of the limitations of...

BPN947: High-Performance Mid-Infrared Optoelectronics

Shu Wang
Naoki Higashitarumizu
Shogo Tajima
2024

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...

BPN983: Materials and Devices for Bright UV LEDs

Shu Wang
2023

Wide band gap semiconductors are crucial for applications in power electronics, displays, solid-state lightning and many other fields. Due to their intrinsic structure and electronic properties, many wide band gap semiconductors can not be intentionally doped as desired, which limits their role in electronic and optoelectronic devices. In this project, we propose tuning the optoelectronic properties of wide band gap semiconductors electrically to enhance its luminescence efficiency.

Project ended: 02/07/2024

Noelle Davis

Graduate Student Researcher
Electrical Engineering and Computer Sciences
Professor Ali Javey (Advisor)
Ph.D. 2025 (Anticipated)

Noelle received her B.S. in Electrical Engineering from Caltech in 2020. She is pursuing her PhD as an NDSEG fellow under the supervision of Prof. Ali Javey. Her research is focused on electrochemical sensing technologies for athletic and healthcare applications, in particular developing and using sweat sensors to understand how non-invasive parameters can reflect deeper physiology. On the side, she rides and races bikes with Cal Cycling.

I K M Reaz Rahman

Graduate Student Researcher
Electrical Engineering and Computer Sciences
Professor Ali Javey (Advisor)
Ph.D. 2026 (Anticipated)

I K M Reaz Rahman is a Ph.D. candidate in the Electrical Engineering and Computer Sciences department at UC Berkeley, working under the supervision of Professor Ali Javey. He received a Master’s degree in 2020 and a Bachelor’s degree in 2017, both in Electrical and Electronic Engineering at Bangladesh University of Engineering and Technology.

Before joining UC Berkeley, Reaz worked on modeling of nanoscale transistors and their impact with scaling. At present, his focus is on characterization of optoelectronic properties in low-dimensional systems.

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Jamie Geng

Graduate Student Researcher
Electrical Engineering and Computer Sciences
Professor Ali Javey (Advisor)
Ph.D. 2028 (Anticipated)