Search

Your search keyword '"Liao, Congwei"' showing total 226 results
Start Over Author "Liao, Congwei" Publication Year Range Last 50 years
226 results on '"Liao, Congwei"'

4. Organic-inorganic hybrid piezotronic bipolar junction transistor for pressure sensing.

Author

Iranmanesh, Emad, Liang, Zihao, Li, Weiwei, Liao, Congwei, Jin, Shunyu, Liu, Chuan, Wang, Kai, Zhang, Shengdong, Doumanidis, Charalampos, Amaratunga, Gehan A. J., and Zhou, Hang

Subjects
JUNCTION transistors, BIPOLAR transistors, PIEZOELECTRICITY, POWER resources, PRESSURE sensors, TRANSCRANIAL magnetic stimulation
Abstract

With the rapid development of the Internet of Things (IoTs), wearable sensors are playing an increasingly important role in daily monitoring of personal health and wellness. The signal-to-noise-ratio has become the most critical performance factor to consider. To enhance it, on the one hand, good sensing materials/devices have been employed; on the other hand, signal amplification and noise reduction circuits have been used. However, most of these devices and circuits work in an active sampling mode, requiring frequent data acquisition and hence, entailing high-power consumption. In this scenario, a flexible and wearable event-triggered sensor with embedded signal amplification without an external power supply is of great interest. Here, we report a flexible two-terminal piezotronic n-p-n bipolar junction transistor (PBJT) that acts as an autonomous and highly sensitive, current- and/or voltage-mediated pressure sensor. The PBJT is formed by two back-to-back piezotronic diodes which are defined as emitter-base and collector-base diodes. Upon force exertion on the emitter side, as a result of the piezoelectric effect, the emitter-base diode is forward biased while the collector-base diode is reverse biased. Due to the inherent BJT amplification effect, the PBJT achieves record-high sensitivities of 139.7 kPa-1 (current-based) and 88.66 kPa-1 (voltage-based) in sensing mode. The PBJT also has a fast response time of <110 ms under exertion of dynamic stimuli ranging from a flying butterfly to a gentle finger touch. Therefore, the PBJT advances the state of the art not only in terms of sensitivity but also in regard to being self-driven and autonomous, making it promising for pressure sensing and other IoT applications. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

5. P‐23: Low Power A‐PWM μLED Pixel Circuit of Progressive‐mode Using Single Sweep Signal for Mobile Displays.

Author

Zhu, Yuxuan, Song, Zhibang, Qian, Lingxiao, Zheng, Xin, Liao, Congwei, and Zhang, Shengdong

Subjects
LOGIC circuits, QUANTUM efficiency, PIXELS, TRANSISTORS
Abstract

An analog pulse‐width‐modulation (A‐PWM) Micro‐LED (μLED) pixel circuit based on low‐temperature‐polysilicon (LTPS) thin‐film transistors (TFTs) for mobile displays is proposed. The progressive‐emission mode is implemented using a single Sweep (SW) signal by in‐pixel logic operation circuits. By adjusting the emission time of the progressive‐emission mode, the μLED is biased with the maximum quantum efficiency (EQE). Consequently, the static power consumption of proposed pixels is reduced by 29.2%, compared with conventional schemes. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

7. P‐6.17: Design of Compact A‐PWM Gate Driver Based on LTPS TFTs for Progressive‐Mode μLED Displays.

Author

Zhu, Yuxuan, Qian, Lingxiao, Song, Zhibang, Zheng, Xin, Liao, Congwei, and Zhang, Shengdong

Subjects
POLYCRYSTALLINE silicon, PULSE width modulation, PULSE width modulation transformers, LED displays, TRANSISTORS, DIODES
Abstract

A compact gate driver using p‐type low‐temperature polycrystalline silicon (LTPS) thin‐film transistors (TFTs) was proposed for Micro‐Light Emitting diodes (μLEDs) display using progressive emission analog pulse‐width modulation (A‐PWM) approach. The gate driver contains a simple waveform shaping module and outputs multiple sweep signals, including SW[n], EM[n], and S[n], by reusing the bootstrap node. Compared with conventional schemes, the proposed gate driver renders static power consumption reduction of the μLED display by 29.2%. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

8. P‐6.13: 3D Stacked Hybrid TFT Integrated Circuits for 1100 PPI AMOLED Display.

Author

Liu, Yunfei, Zhu, Yuxuan, Chang, Lu, Liao, Congwei, Lu, Lei, and Zhang, Shengdong

Subjects
PIXELS
Abstract

This paper studies high‐resolution AMOLED displays pixel and driving circuits using 3D stacking LTPS and oxide hybrid TFT integration technology systematically. It is demonstrated the OLED display resolution reaches 1167 PPI when the minimum line width/line spacing is reduced to 1 μm/0.5 μm. In addition, peripheral row and column drive circuits for the high display resolution were also illustrated. Good dynamic performance of the designed driving circuits was obtained thanks to the 3D TFTs. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

21. P‐4: ΔVTH and VSS IR rise Compensable PAM and PWM Combined Oxide TFTs Mini‐LED Pixel Circuit Working at Low Voltage.

Author

Shao, Zhibo, Fu, Jia, Liao, Congwei, Zou, Zhongfei, Zhong, Dezhen, and Zhang, Shengdong

Subjects
LOW voltage systems, LED displays, PIXELS, ERROR rates, OXIDES, LIGHT emitting diodes, PULSE width modulation transformers
Abstract

This paper presents a PAM and PWM combined Mini‐LED pixel circuit based on oxide TFTs. In the PAM part, a constant current (1mA) allows Mini‐LEDs work at peak efficiency and reduce power consumption. A source follower structure compensates for ΔVTH and VSS IR rise, which has only one TFT on current path, so that the pixel circuit works at low voltage. In the PWM part, a diode connected structure compensates for ΔVTH. Simulation results show that the current error rate is less than 0.81% when ΔVTH of PAM part is within ±3 V. When VSS rises less than 3 V, the current error rate is less than 7.22%. When ΔVTH of PWM part is +3 V, emission time variation is reduced by 99.29% compared with the circuit without compensation. The supply‐voltage can be reduced from 19.7 V to 15 V thanks to the proposed Mini‐LED pixel circuit. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

26. P‐4: ΔVTHand VSSIR rise Compensable PAM and PWM Combined Oxide TFTs Mini‐LED Pixel Circuit Working at Low Voltage

Author

Shao, Zhibo, Fu, Jia, Liao, Congwei, Zou, Zhongfei, Zhong, Dezhen, and Zhang, Shengdong

Abstract

This paper presents a PAM and PWM combined Mini‐LED pixel circuit based on oxide TFTs. In the PAM part, a constant current (1mA) allows Mini‐LEDs work at peak efficiency and reduce power consumption. A source follower structure compensates for ΔVTH and VSS IR rise, which has only one TFT on current path, so that the pixel circuit works at low voltage. In the PWM part, a diode connected structure compensates for ΔVTH. Simulation results show that the current error rate is less than 0.81% when ΔVTH of PAM part is within ±3 V. When VSS rises less than 3 V, the current error rate is less than 7.22%. When ΔVTH of PWM part is +3 V, emission time variation is reduced by 99.29% compared with the circuit without compensation. The supply‐voltage can be reduced from 19.7 V to 15 V thanks to the proposed Mini‐LED pixel circuit.

Published
2023
Full Text
View/download PDF

29. Influence of Temperature on the Illumination Time Dependent Photocurrent of Amorphous InZnO Thin-Film Transistors

Author

Changhui Fan, Lei Lu, Liao Congwei, Xiaoliang Zhou, Shengdong Zhang, Jie Chen, and Letao Zhang

Subjects
Photocurrent, Arrhenius equation, symbols.namesake, Materials science, Thin-film transistor, Screening effect, Analytical chemistry, symbols, Activation energy, Temperature measurement, Arrhenius plot, Amorphous solid
Abstract

The influence of temperature on the time dependent photocurrent $(I_{ph})$ of amorphous InZnO (a-IZO) thin-film transistors (TFTs) under illumination with different wavelengths is investigated. Strong dependence of photocurrent on temperature is observed with the photocurrent follows the Arrhenius relationship. As the I ph increases with the increasing illumination time, the activation energy $(E_{a})$ of I ph extracted from the Arrhenius plots shows two trends, with the E a decreases firstly, and increases subsequently after a minimal value is reached. The decreasing and increasing trends suggest that the barrier lowering effect at the source side near the back channel and the screening effect of the accumulated photo-induced ionized oxygen vacancies within the channel region near the front channel are the dominating physical mechanisms of I ph , respectively.

Published
2021

36. 14‐3: OLEDoS Microdisplay with OLED Threshold Voltage Detection and Fast‐Progressive Compensation

Author

Lam, Hing-Mo, primary, Qiu, Hezi, additional, Li, Chenglin, additional, Wen, Jinyuan, additional, Bai, Wenlong, additional, Huang, Jie, additional, Xu, Chen, additional, Huo, Xinxin, additional, Yi, Shuiping, additional, Zeng, Weiling, additional, Zhang, Dewei, additional, Lei, Tengteng, additional, Lu, Silin, additional, An, Junjun, additional, Liao, Congwei, additional, Zhang, Min, additional, Jiao, Hailong, additional, and Zhang, Shengdong, additional

Published
2021
Full Text
View/download PDF

46. P‐9: Student Poster:Two‐Mode PWM Driven Micro‐LED Displays with Dual‐Gate Metal‐Oxide TFTs

Author

Fu, Jia, Liao, Congwei, Qiu, Hezi, Jin, Shuang, Yao, Jiangbo, Zeng, Limei, Zhang, Xin, and Zhang, Shengdong

Abstract

A two‐mode pulse width modulation (PWM) pixel circuit is proposed for Micro‐LED display. The proposed driving method divides the consecutive 8 sub‐frames (256 gray levels) into low‐bit and high‐bit subframes, which are respectively driven by simultaneous emission (SE) and progressive emission (PE) modes. Compared with the traditional PWM driving scheme, the proposed one shows an increased effective luminous time ratio by 40% for a frame rate of 120Hz, which benefits higher power conversion efficiency. There are only 5 dual‐gate metal‐oxide transistors for the pixel circuit, while a source‐follower structure is adopted to extract the threshold‐voltage shift(ΔVth). Simulation results demonstrate that the current error rates can be reduced to 2% with ΔVth of ± 1 V for various grayscales.

Published
2022
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results