Ali Javey (Advisor)

Research Advised by Professor Ali Javey

Javey Group:  List of Projects | List of Researchers

Yifei Zhan

Graduate Student Researcher
Electrical Engineering and Computer Sciences
Professor Ali Javey (Advisor)
Ph.D. 2029 (Anticipated)

BPNX1025: In-Sensor Visible to Mid-Infrared Spectral Machine Vision

Dehui Zhang
Jamie Geng
Shifan Wang
Hyong Min Kim
2024

Multispectral and hyperspectral imaging are important optical inspection technologies. They collect the spatial and spectral information of the incidental light into 3D hypercubes, which can be post-processed into material and structural mapping of the scene. However, acquiring and analyzing the 3D hypercubes set great challenges in data collection, transportation, storage, and computation. The much higher energy, bandwidth, and memory budgets limit the implementation of high-speed, high-resolution hyperspectral imaging to achieve intelligent machine vision. This project introduces an...

Shifan Wang

Visiting Scholar Researcher
Electrical Engineering and Computer Sciences
Professor Ali Javey (Advisor)
Ph.D. 2024 (Anticipated)

BPNX1031: Scalable Infrared Photodetectors based on Large-Grain Tellurium Film (New Project)

Hyong Min Kim
Naoki Higashitarumizu
2024

Tellurium is a narrow-gap, p-type semiconductor with promising potential for future electronic and optoelectronic devices. Te’s band gap can be tuned from 0.31 eV in bulk form to 1.04 eV in monolayer form. Unlike many other competing 2D semiconductors, Te is air-stable and can be deposited on a substrate of choice by thermal evaporation or solution synthesis. Photodetectors based on solution-synthesized Te nanoflakes have already been demonstrated, with specific detectivity in near-IR at or above 10^9 Jones. However, solution-synthesis of Te nanoflakes is not scalable, and...

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

Theodorus Jonathan Wijaya
Naoki Higashitarumizu
Shogo Tajima
Shifan Wang
Hyong Min Kim
Dehui Zhang
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...

BPNX1028: Large Scale Synthesis of Optically Active Tellurium-Based Material (New Project)

Shu Wang
Naoki Higashitarumizu
2024

Large-scale growth of high-quality semiconductors, the active component of devices, is the foundation of modern electronics. Recently, tellurium (Te) was identified as a promising material for optoelectronics due to its appealing optical properties and potential low-temperature wafer-scale production. In this project, we will develop a new method for controlled and scalable production of optically active tellurium.

Project is currently funded by: Federal

BPNX1026: Strong, Tunable Mid-IR Emission from Black Phosphorous Ink Film

Naoki Higashitarumizu
Hyong Min Kim
Shu Wang
2024

Black Phosphorus (bP) is a highly promising host material for future optoelectronic devices operating in the mid-wavelength infra-red (MWIR) regime of 3-5 um. bP is the most stable allotrope of phosphorous with a bulk direct bandgap of 0.3 eV that is highly tunable by alloying, applying strain, and varying the thickness, and with many remarkable electronic and optical properties ranging from low surface recombination velocity to high carrier mobility. Both MWIR LEDs and photodetectors based on mechanically exfoliated bP flakes operating at room temperature have shown superior...

BPN984: Large-Area Processable Two-Dimensional Material Films

Naoki Higashitarumizu
Shu Wang
Hyong Min Kim
Theodorus Jonathan Wijaya
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

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...

BPNX1023: CMOS-Compatible Doping of 2D Semiconductors

Inha Kim
Naoki Higashitarumizu
2024

2D materials are among the most promising candidates for next-generation semiconductor devices due to their exceptional electronic transport properties and composition of a single atomic layer, which offers significant advantages for integration density. However, high contact resistance and challenges in doping present obstacles to their practical applications. In this work, we aim to explore various methods to overcome these issues and achieve technological breakthroughs that will enable these materials to become integral components in a wide range of applications.

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