Session Overview |
Wednesday, May 29 |
14:00 |
GaN LEDs for Environmental Sensing
* Pei-Cheng Ku, Department of Electrical Engineering and Computer Science, University of Michigan, United States of America Environmental sensing plays a crucial role in pursuing a green society. Robust, energy-efficient sensors that can be deployed remotely or/and part of Internet of Things (IoTs) can improve sustainability, reduce waste and overhead, promote safety, and increase awareness. In this talk, I will present two optical sensors based on GaN LEDs: an on-chip optical spectrometer and a tactile sensor. Both are derived from GaN micro-LEDs for display applications and share the same operating principle, the local strain engineering enabled by GaN’s strong piezoelectric effect. I will discuss these sensors' unique advantages and challenges. Finally, I will present our approach to system integration and the use of machine learning to enhance the system functionality. |
14:35 |
Tensile-strained InGaAs quantum dot light sources for mid-IR environmental monitoring
* Paul Simmonds, Tufts University, United States of America Efficient light sources operating in the mid-infrared (mid-IR) region of the electromagnetic spectrum are needed for environmental monitoring applications such as greenhouse gas regulation. Using tensile strain to modify their band structure, we can red-shift the light emitted by In0.5Ga0.5As quantum dots (QDs) from 1.6 µm to 3–4 µm. We show that these QDs are defect-free and that their emission is tunable with molecular beam epitaxy (MBE) growth conditions, paving the way for novel mid-IR LEDs and lasers. |
15:00 |
Type-II kappa/beta gallium oxide phase heterojunction for deep ultraviolet self-powered photodetection
Patsy Arely Miranda Cortez, Advanced Semiconductor Lab, Saudi Arabia Yi Lu, Advanced Semiconductor Lab, Saudi Arabia Xiao Tang, Advanced Semiconductor Lab Zhiyuan Liu, Advanced Semiconductor Lab, Saudi Arabia Vishal Khandelwal, Advanced Semiconductor Lab Shibin Krishna, Advanced Semiconductor Lab Xiaohang Li, Advanced Semiconductor Lab This study demonstrates the β-Ga2O3/κ-Ga2O3 phase heterojunction, a type-II III-oxide heterojunction. The experiment reveals a sharp interface and significant band offsets of 0.65 eV for 'E_v and 0.71 eV for 'E_c. This unique band alignment shows promise for self-powered deep ultraviolet (DUV) detection. The fabricated heterojunction photodetector exhibits higher responsivity (17.8 mA/W) under DUV illumination and zero external bias compared to bare β-Ga2O3 and κ-Ga2O3 photodetectors. This work highlights the potential of the β-Ga2O3/κ-Ga2O3 heterojunction for Ga2O3-based technologies. |
15:15 |
Highly stable green LEDs based on strain relaxed nanorod arrays
* Nirmal Anand, INRS-EMT, Canada Sharif Sadaf, INRS-EMT, Canada InGaN/GaN green micro-light emitting diodes (μLEDs) based on nanorod arrays were fabricated via a top-down approach. The device exhibits minimal peak wavelength shift on varying current densities over three orders of magnitude. These results indicate highly suppressed occurrence of quantum confined Stark effect (QCSE) due to the strain relaxation on the free surfaces of InGaN ~21% multi-quantum wells (MQWs) in the nanorods. This work establishes a viable approach to achieving high indium composition InGaN/GaN μLED pixels free from spontaneous and piezoelectric polarization induced QCSE. |
15:30 |
Multiphysics Design and Analysis of Silver-Based Low-Emissivity Coating Technology
* Khashayar Ghaffari, Ansys Canada Ltd., Canada Anthony Leger, Ansys Inc. Duane Mateychuk, Ansys Inc. Amrita Pati, Ansys Canada Ltd. Laila Salman, Ansys Canada Ltd. Low-Emissivity (Low-E) Technology is a unique and cost-effective solution for Modern Energy Saving Windows. In this work, we leverage simulation to characterize the optical and high frequency performance for several Silver-Based Low-E Coating designs. We demonstrate close match with reported measurements for double and triple silver coatings. Wave optics and ray tracing analysis are combined to account for sub-micron features while modeling the larger window models. We also perform high frequency analysis to characterize the signal attenuation through the windows. |