Ali Javey (Advisor)

Research Advised by Professor Ali Javey

BPN983: Materials and Devices for Bright UV LEDs (New Project)

Shu Wang
2022

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.

BPN988: Low Voltage AC Electroluminescence in Silicon MOS Capacitors (New Project)

I K M Reaz Rahman
2022

Low power silicon based light source and detector are attractive for on-chip photonic circuits given their ease of process integration. However, conventional silicon light emitting diodes emit photons with energies near the band-edge where the corresponding silicon photodetectors lack responsivity. On the other hand, previously reported hot carrier electroluminescent silicon devices utilizing a reverse biased diode require high operating voltages. Here, we investigate hot carrier electroluminescence in silicon metal-oxide-semiconductor capacitors operating under transient...

I K M Reaz Rahman

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

BPN979: Developing Sweat Rate Sensors Using New Sensing Modalities (New Project)

Ashwin Aggarwal
Manik Dautta
Luis Fernando
Ayala Cardona
2022

The skin surface naturally secretes sweat for thermoregulation during sedentary and physical activities at varying rates, which can sometimes indicate underlying health conditions such as nerve damages or metabolic disorders. As measuring low secretion rates poses a challenge for traditional microfluidic devices, we present new ways to collect such sweat rates precisely.

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

Jongchan Kim
Vivian Wang
2022

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...

BPN984: Large-Area Processable Luminescent Black Phosphorus (New Project)

Kyuho Lee
Niharika Gupta
2022

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.

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

Noelle Davis
Ashwin Aggarwal
Manik Dautta
Luis Fernando
Ayala Cardona
2022

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...

BPN925: Perfectly Bright Low Dimensional Semiconductors

Shiekh Zia Uddin
Jongchan Kim
2022

Most optoelectronic devices operate at high photocarrier densities, where all semiconductors suffer from enhanced nonradiative recombination. Nonradiative processes proportionately reduce photoluminescence (PL) quantum yield (QY), a performance metric that directly dictates the maximum device efficiency. Although transition metal dichalcogenide (TMDC) monolayers exhibit near-unity PL QY at low exciton densities, nonradiative exciton-exciton annihilation (EEA) enhanced by van-Hove singularity (VHS) rapidly degrades their PL QY at high exciton densities and limits their utility in...