Ali Javey (Advisor)

Research Advised by Professor Ali Javey

Javey Lab: Berkeley Engineers Develop Multicolored Light-Emitting Array on a Single Chip

May 10, 2023

An array of light-emitting devices with 49 different, individually addressable colors.

An array of light-emitting devices with 49 different, individually addressable colors. (Image by Vivian Wang) With limitless colors, the device may lead to advances in spectroscopy May 10, 2023 by Marni Ellery

Multicolored light-...

Highly Multicolored Light-Emitting Arrays for Compressive Spectroscopy

Vivian Wang
Shiekh Zia Uddin
Junho Park
Ali Javey

Miniaturized, multicolored light-emitting device arrays are promising for applications in sensing, imaging, computing, and more, but the range of emission colors achievable by a conventional light-emitting diode is limited by material or device constraints. In this work, we demonstrate a highly multicolored light-emitting array with 49 different, individually addressable colors on a single chip. The array consists of pulsed-driven metal-oxide-semiconductor capacitors, which generate electroluminescence from microdispensed materials spanning a diverse range of colors and spectral shapes,...

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

Naoki Higashitarumizu
Kyuho Lee

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...

BPN946: Sensor for Natural Sweat Analysis

Sorour Darvishi

Wearable sweat sensors have emerged as attractive platforms for non-invasive health monitoring. While most sweat sensors have relied on exercise or chemical stimulation to generate sweat, natural thermoregulatory sweat is an attractive alternative as it can be accessed during routine and even sedentary activity without impeding user lifestyles, while also potentially preserving correlations between sweat and blood biomarkers. For rapid accumulation of natural sweat that enables quick, single-point measurement of sweat analytes, we develop a simple, skin-attachable sensing platform to...

Sorour Darvishi

Postdoctoral Researcher
Electrical Engineering and Computer Sciences
Professor Ali Javey (Advisor)

BPN982: Color-Tunable Alternating Current Light Emitting Diodes (New Project)

Jongchan Kim
Vivian Wang

Alternating current (AC) driven light emitting devices (LEDs) are recently dragging attention due to its efficient color tunability. These devices consist of multilayer structure as the direct current (DC) driven LEDs, but the multilayer structure has drawbacks such as the large amount of material usage that increases the fabrication cost, and the difficult yield control due to a number of processing steps. In contrast, a recently demonstrated AC driven LED with a single contact has several advantages compared to the previous structures such as simple device structure, diverse...

Shogo Tajima

Visiting Industry Fellow
Azbil Corp
Professor Ali Javey (Advisor)

BPN920: Robust, Multimodal Sweat Sensors with High-Throughput Fabrication

Noelle Davis
Ashwin Aggarwal
Sorour Darvishi

In the field of sweat monitoring, many sensors have been piloted with one or two subjects over limited periods of time, but there is a need for prolonged, large-scale studies to establish reliable physiological correlations that account for diverse subjects, activities, and environments. Chemical sensors provide the concentration of analytes of interest, including sodium, potassium, and glucose, while sweat rate sensors provide standalone information on nerve function and hydration. Monitoring both of these in parallel will enable the decoding of concentrations of analytes that are...

BPN988: Modulation of Optoelectronics in Quantum Dot Film

I K M Reaz Rahman
Naoki Higashitarumizu

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...