Browsing by Author "Zan, Hsiao-Wen"

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2-V operated flexible vertical organic transistor with good air stability and bias stress reliability
(2017-11-01)
Huang, Kuan-Min
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Lin, Hung-Cheng
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Kawashima, Kazuaki
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Osaka, Itaru
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Zan, Hsiao-Wen
In this work, we demonstrated a vertical organic transistor using air-stable material to exhibit good lifetime, good bias-stress reliability, and low operation voltage on a flexible plastic substrate in air ambient. With a synthesized NTz-based semiconducting polymer, the proposed space-charge-limited transistor (SCLT) delivers high on-off current ratio of 160000 and high output current density of 10 mA/cm(2) at about 2 V. Without encapsulation, the proposed transistor keeps stable current-voltage relationship for 180 days and has only 0.1 V threshold voltage shift after 5000 s bias stress. No significant degradation can be observed after 1000-times bending and a maximum gain of 14 can be obtained when connecting the flexible transistor with a resistor to form an inverter. (C) 2017 Elsevier B.V. All rights reserved.
A 0.05 V driven ammonia gas sensor based on an organic diode with a top porous layered electrode and an air-stable sensing film
(2019-06-07)
Madhaiyan, Govindasamy
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Chen, Chao-Hsuan
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Wu, Yi-Chu
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Horng, Sheng-Fu
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Zan, Hsiao-Wen
In this work, we successfully demonstrated an extremely-low-voltage (0.05 V) gas sensor based on a vertical organic diode with work-function-matched electrodes. With the designed electrodes (MoO3/Al vs. Al), the built-in field in the vertical diode is greatly reduced and hence the diode can be turned on at a very low voltage. By producing nanometer pores in the top electrode, the diode becomes a very sensitive gas sensor to detect ammonia in parts-per-billion (ppb) concentrations. Upon reducing the voltage from 5 V to 0.05 V, this sensor device shows an over 5-times enhancement in the sensitivity. The air-stable sensing film also exhibits a lifetime of 30 days in air. Finally, by connecting with an organic photovoltaic (OPV) device, the gas sensor can be directly powered and switched on by irradiating light on the OPV.
A 1-V operated polymer vertical transistor with high on/off current ratio
(2009)
Chao, Yu-Chiang
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Tsai, Wu-Wei
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Chen, Chun-Yu
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Zan, Hsiao-Wen
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Meng, Hsin-Fei
A 3.2 mW MIXED-SIGNAL READOUT CIRCUIT FOR AN ORGANIC VERTICAL NANO-JUNCTIONS SENSOR
(2016)
Chao, Paul C. -P.
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Su, Chin-I
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Tran, Trong-Hieu
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Zan, Hsiao-Wen
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電子工程學系及電子研究所
A new sensitivity organic vertical nano-junctions (VNJ) sensor for ammonia detection and its readout system are presented in this study. The designed ammonia sensor, VNJ-P3HT diode, is a simple structure with real-time response, high reproducibility and low-cost sensor. Along with the designed sensor, a precision and robust readout circuit is designed and successfully implemented as the proposed chip in this study. To utilize for a novel organic bio-chip, a particular readout system is presented that can acquire signal, compute and display concentration values of ammonia without using microcontroller. The chip is fabricated by the TSMC 0.18-mu m 1P6M 3.3V mixed signal CMOS process technique for verification. Experiment results show that the average resolution is 70.48mV/log(ppm) in a short transient time response, 50 seconds, as compared to prior study, 200 seconds. Error rate, average noise and detection rate reliability are 2.86%, 123 mu Vrms, and 99.6%, respectively. This chip could be suitable for application in cars, cell phones, watches, etc.
A 70nW, 0.3V Temperature Compensation Voltage Reference Consisting of Subthreshold MOSFETs in 65nm CMOS Technology
(2016)
Lu, Ting-Chou
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Ker, Ming-Dou
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Zan, Hsiao-Wen
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電子工程學系及電子研究所
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光電工程學系
Being operated with 0.3V supply voltage in a standard 65nm CMOS process, a new CMOS temperature compensated voltage reference circuit is proposed with subthreshold transistors and native nMOS. The reference drain current provided by the gate voltage of a subthreshold nMOS output transistor is nearly independent of temperature due to the existence of mutual compensation of mobility and threshold voltage variation. The new proposed temperature compensated voltage reference circuit functions well with the output voltage VREF of 168 mV at room temperature as no extra laser trimming is needed after fabrication. The total power consumption is about 70nW. With the VDD power supply of 0.3V, the temperature coefficient (TC) of voltage reference circuit is 105 ppm/degrees C as temperature varies from -20 degrees C to 100 degrees C. The chip size of the fabricated bandgap reference circuit is 0.0053mm(2).
A 8 Phases 192 MHz Crystal-Less Clock Generator with PVT Calibration
(2017-01)
Lu, Ting-Chou
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Ker, Ming-Dou
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Zan, Hsiao-Wen
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Liu, Jen-Chieh
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Lee, Yu
A multi-phase crystal-less clock generator (MPCLCG) with a process-voltage-temperature (PVT) calibration circuit is proposed. It operates at 192 MHz with 8 phases outputs, and is implemented as a 0.18pm CMOS process for digital power management systems. A temperature calibrated circuit is proposed to align operational frequency under process and supply voltage variations. It occupies an area of 65 mu m x 75 mu m and consumes 1.1 mW with the power supply of 1.8 V. Temperature coefficient (TC) is 69.5 ppm/degrees C from 0 to 100 degrees C, and 2-point calibration is applied to calibrate PVT variation. The measured period jitter is a 4.58-ps RMS jitter and a 34.55-ps peak-to-peak jitter (P2P jitter) at 192 MHz within 12.67k-hits. At 192 MHz, it shows a 1-MHz-offset phase noise of -102 dBc/Hz. Phase to phase errors and duty cycle errors are less than 5.5% and 4.3%, respectively.
A 8 Phases 192 MHz Crystal-Less Clock Generator with PVT Calibration
(2017-01)
Lu, Ting-Chou
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Ker, Ming-Dou
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Zan, Hsiao-Wen
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Liu, Jen-Chieh
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Lee, Yu
A multi-phase crystal-less clock generator (MPCLCG) with a process-voltage-temperature (PVT) calibration circuit is proposed. It operates at 192 MHz with 8 phases outputs, and is implemented as a 0.18pm CMOS process for digital power management systems. A temperature calibrated circuit is proposed to align operational frequency under process and supply voltage variations. It occupies an area of 65 mu m x 75 mu m and consumes 1.1 mW with the power supply of 1.8 V. Temperature coefficient (TC) is 69.5 ppm/degrees C from 0 to 100 degrees C, and 2-point calibration is applied to calibrate PVT variation. The measured period jitter is a 4.58-ps RMS jitter and a 34.55-ps peak-to-peak jitter (P2P jitter) at 192 MHz within 12.67k-hits. At 192 MHz, it shows a 1-MHz-offset phase noise of -102 dBc/Hz. Phase to phase errors and duty cycle errors are less than 5.5% and 4.3%, respectively.
A Fast Readout Circuit for an Organic Vertical Nano Junction Sensor
(2016-01-01)
Trong-Hieu Tran
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Chao, Paul C. -P.
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Su, Chin-I
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Zan, Hsiao-Wen
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電機工程學系
A fast mixed-signal readout circuit for high sensitivity organic vertical nano-junctions (VNJ) ammonia sensor detection is proposed in this study. Accompanying with the ammonia sensor, a low power, fast response and high resolution readout circuit is designed and successfully taped-out in this study. The analog front-end circuit includes a pre-amplifier, a sample and hold (S/H) circuit, a differential current, a pulse width modulation (PWM) circuit, an automatically sensing and reset (S/R) circuit. The digital back-end is realized by cell-based technology to compute and display concentration values instantaneously. The chip is fabricated by the TSMC 0.18-um 1P6M 3.3V mixed-signal CMOS process technique for verification. The chip area is 1.5 x 1.6 mm(2). while power consumption is 3.2 mW. Experiment results show a strong linear relationship exists between differential S/R output slope and the gas concentration level in a logarithm scale, which is critically beneficial to sensor design. In results, the readout circuit has fast responses, 50 seconds, based on the auto-sensing circuit catching different slope coefficient of the signal in transient time. The resolution is 70.48mV/log(ppm) while error rate, average noise and detection rate reliability are 2.86%, 123 mu Vrms, and 99.6%, respectively. This chip could be suitable for applications in cars, cell phones, watches, etc.
A low-cost miniaturized colorimetric sensor with vertically-stacked semi-transparent finger-type organic photo detector for formaldehyde sensing
(2019-10-01)
Lin, Ching-Fu
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Zan, Hsiao-Wen
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Lu, Chia-Jung
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Meng, Hsin-Fei
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Soppera, Olivier
We proposed a sensitive colorimetric sensing system using a paper-like sensing layer on top of a vertically stacked finger-type organic photodetector (OPD) and commercial light-emitting diode (LED). The stacked OPD/LED device was small, with an area of 0.8 cm x 0.5 cm that was even smaller than a coin. Using commercial colorimetric formaldehyde (HCHO) sensing molecules to form the sensing layer, the stacked detecting system successfully detected HCHO of concentrations ranging from 40 to 1000 ppb within 20 min. Critical parameters affecting the sensitivity were investigated. The final system exhibited a stable calibration curve over 60 days. The long lifetime was attributed to using 2,6-Bis(trimethyltin)-4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo [1,2-b:4,5-b']dithiophene (PBDTTT-C-T): phenyl-C71-butyric acid methyl ester (PC71 BM) to serve as a blended system and using the current variation ratio to represent the sensing response.
A low-cost, portable and easy-operated salivary urea sensor for point-of-care application
(2019-05-01)
Wang, Kuan-Hsun
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Hsieh, Ju-Chun
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Chen, Chang-Chiang
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Zan, Hsiao-Wen
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Meng, Hsin-Fei
Salivary urea was reported to be a useful biomarker to reflect the blood urea nitrogen in chronic kidney disease patients. However, as a new biomarker, enormous clinical trials are required to define the intended-use and to verify the specification. In this report, we demonstrated a low-cost easy-operated real-time sensing system (optical fiber-urea-sensing, OFUS, system) to detect salivary urea. We aim to make the system easily reproduced by the community to stimulate abundant clinical tests worldwide. The OFUS system is composed of a simple three-dimensional printed tank to link with two optical fibers, one connecting with a commercial light-emitting diode to deliver the input light signal, the other connecting with a commercial cadmium sulfide photo-conductive cell to detect the sensing signal. To allow on-site detection without any sample pretreatment, only 1 mu l saliva is needed to be mixed with 10 mu l urease solution and 90 mu l pH indicator solution in the reaction tank and the detection time is only 20 s. A stable and reproducible calibration curve can be easily built with a detection range as 24-300 mg/dL. The OFUS system successfully detected saliva with added synthetic urea and samples from chronic kidney disease patients. A good agreement between the OFUS system and the commercial kit was obtained. A good correlation between salivary urea and the blood urea nitrogen was also confirmed.
A New Gas Sensor of a Thin-Film Diode and Low-Power, Area-Efficient Readout Circuit
(2013)
Chen, Hung-Che
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Chao, Paul C. -P.
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Lin, Wei-Chu
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Sun, Hsiang-Fang
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Dai, Ming-Zhi
The study presents a new gas sensor made of a novel organic diode with vertical nano-junctions and its low-power, area-efficient readout circuit. There are seven parts included in the readout system. First part is a preamplifier, which is composed of trans-impedance to convert the output current of a gas sensor into voltage. Second part is a peak-detect-and-hold circuit. It can detect the maximum voltage and holds its value, the initial value. Third part is a divider, which is used to calculate the ratio of saturation current to initial current. Fourth part is the saturation detector, which is used to detect when the output current of the VNJ-P3HT diode doesn\'t change anymore (that is, the responses are saturated). Fifth part is the auto-reset circuit, which is used to detect when the sensor device starts to react with gas and reset the voltage value of the peak detect-and-hold circuit. Sixth part is a logic gate and a buffer. When the sensor device is reacting with gas and the responses are saturated, the response result is outputted through the logic gate and buffer. Otherwise, the zero is outputted. Seventh part is a micro-processor control unit (MCU). STM32 is the CPU of proposed MCU by ALIENTEK. The ADC of MCU is used to transform the output data of readout circuit. Then the LCD displays the results. The designed circuit is accomplished by Taiwan Semiconductor Manufacturing Company (TSMC) 0.35 mu m 2P4M 3.3V mixed-signal CMOS process.
A new readout/driver circuitry for an optical vibration sensor
(2017-01-01)
Wu, Chun-Hao
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Chao, Paul C. -P.
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Wu, Yi-Cheng
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Sauter, Thilo
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Zan, Hsiao-Wen
This work presents research results on designing the drive and readout circuits for a newly-developed optical vibrations sensor. Tes sensor consists of organic light-emitting diodes (OLEDs) and photodetectors (OPDs) and micro-structure to realize the function of vibration sensing. Proper operations of OLEDs and OPDS needs a driver and a readout circuit, respectively. A driver circuit is designed for driving and controlling OLED light; also, a readout circuit is designed to acquire current signal from OPD and then converts it to digital signals by an analog-to-digital converter (ADC). In addition to readout circuit, a front-end amplifier called transimpedance amplifier (TIA) is designed for converting the output current of the OPDs. The TIA is followed by an IA and LPF for better signal quality before a SAR ADC designed for converting the vibration amplitude to digits. The resolution of 10-bit ADC sub-circuit is 1.95mV/LSB. It is suitable for OPD current output. Moreover, a pulse width modulation (PWM) driver circuit which is designed with frequency output 200 KHz is suitable for driving OLED. The proposed circuit is fabricated by TSMC 0.35-mu m CMOS process where the area is 4.5 mm2 for the whole chip while power consumption is 7.808 mW.
A Novel Readout Circuit for an OTFD Gas Sensor with a New Front-end Trans-impedance Amplifier
(2011)
Lin, Wan-Jun
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Chao, Paul C. -P.
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Lin, Shir-Kuan
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Zan, Hsiao-Wen
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電機工程學系
The study proposes a new readout circuit for an organic gas sensor. The readout circuit consists of a preamplifier, a sample and hold circuit and a differential current amplifier. A preamplifier composed of trans-impedance to convert the output current of a gas sensor into voltage. The sample and hold circuit memorizes various voltages according to distinct designed time instants in a target gas environment. At the same time it is equipped with the advantage of repeated detections by the controlling signals which determine the frequency of switch. The differential current is amplified by a differential current amplifier and is attributable to the voltages of sample and hold circuits using current mirror framework. Flowing through the resistance load, the differential current is converted into output voltage. A microprocessor control unit (MCU) acquires and stores the outputs in order to determine gas concentration database of pre-measured which are contrast. The designed circuit is accomplished by Taiwan Semiconductor Manufacturing Company (TSMC) 0.35 mu m 2P4M 3.3V mixed-signal CMOS process.
A solvent-free lift-off method for realizing vertical organic transistors with low leakage current and high ON/OFF ratio
(2016-04)
Fang, Xiang
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Lin, Chia-Ho
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Sun, Yung-Tai
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Chin, Huei-Tzu
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Zan, Hsiao-Wen
A solvent-free lift-off method has been introduced to fabricate the aluminum nano-hole array with diameter down to 80 nm as the base electrode for a vertical organic transistor. The imprinted vertical organic transistor exhibited base leakage current density as low as 5 x 10(-5) mA/cm(2) and high ON/OFF current ratio as high as 10(5). (C) 2016 Elsevier B.V. All rights reserved.
A Versatile Method to Enhance the Operational Current of Air-Stable Organic Gas Sensor for Monitoring of Breath Ammonia in Hemodialysis Patients
(2019-04-01)
Yu, Shang-Yu
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Tung, Tin-Wei
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Yang, Hong-Yu
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Chen, Guan-Yu
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Shih, Che-Chi
Point-of-care (POC) application for monitoring of breath ammonia (BA) in hemodialysis (HD) patients has emerged as a promising noninvasive health monitoring approach. In this context, many organic gas sensors have been reported for BA detection. However, one of the major challenges for its integration with affordable household POC application is to achieve stable performance for accuracy and high operational current at low voltage for low-cost read-out circuitry. Herein, we exploited the stability of the Donor Acceptor polymer on the cylindrical nanopore structure to realize the sensors with a high sensitivity and stability. Then, we proposed a double active layer (DL) strategy that exploits an ultrathin layer of Poly(3-hexylthiophene-2,5-diyl) (P3HT) to serve as a work function buffer to enhance the operational current. The DL sensor exhibits a sustainable operational current of microampere level and a stable sensing response even with the presence of P3HT layer. This effect is carefully examined with different aspects, including vertical composition profile of DL configuration, lifetime testing on different sensing layer, morphological analysis, and the versatility of the DL strategy. Finally, we utilize the DL sensor to conduct a tracing of BA concentration in two HD patients before and after HD, and correlate it with the blood urea nitrogen (BUN) levels. A good correlation coefficient of 0.96 is achieved. Moreover, the feasibility of DL sensor integrated into a low-cost circuitry was also verified. The results demonstrate the potential of this DL strategy to be used to integrate organic sensor for affordable household POC devices.
Accurate real-time sensing tip for aqueous NO with optical fibers embedded in active hydrogel waveguide
(2018-02-01)
Chung, Chieh-Wen
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Tsai, May-Jywan
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Lin, Peng-Wei
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Huang, Ding-Wen
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Wang, Kuan-Hsun
A NO sensing tip is made by inserting two parallel optical fibers inside a poly 2-hydroxyethyl methacrylate (PolyHEMA) hydrogel waveguide mixed with the probe molecule 1, 2-Diaminoanthraquinone (DAQ). There is a length difference of 1 mm between the two fibers, and the light has to propagate through the difference from the short fiber to the long fiber. The total cross section area of the active hydrogel waveguide embedded with the fibers is only 3mm x 1.2 mm. For practical use the tip is housed in a needle for mechanical protection and the sensing tip is able to detect aqueous NO concentration around 1 mu M with time resolution about 5 minutes. Such a sensing tip can be used to monitor the medical conditions inside the brain after a stroke or a brain injury. (C) 2018 Author(s).
Achieving a Good Life Time in a Vertical-Organic-Diode Gas Sensor
(2014-09-01)
Dai, Ming-Zhi
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Chen, Yen-Ho
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Chuang, Ming-Yen
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Zan, Hsiao-Wen
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Meng, Hsin-Fei
In this study, we investigate the keys to obtain a sensitive ammonia sensor with high air stability by using a low-cost polythiophene diode with a vertical channel and a porous top electrode. Poly(3-hexylthiophene) (P3HT) and air-stable poly(5,5'-bis(3-dodecyl-2-thienyl)-2,2'-bithiophene) (PQT-12) are both evaluated as the active sensing layer. Two-dimensional current simulation reveals that the proposed device exhibits numerous connected vertical nanometer junctions (VNJ). Due to the de-doping reaction between ammonia molecules and the bulk current flowing through the vertical channel, both PQT-12 and P3HT VNJ-diodes exhibit detection limits of 50-ppb ammonia. The P3HT VNJ-diode, however, becomes unstable after being stored in air for two days. On the contrary, the PQT-12 VNJ-diode keeps an almost unchanged response to 50-ppb ammonia after being stored in air for 25 days. The improved storage lifetime of an organic-semiconductor-based gas sensor in air is successfully demonstrated.
Achieving good bias stress reliability in organic transistor with vertical channel
(2014-07-01)
Lin, Hung-Cheng
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Zan, Hsiao-Wen
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Meng, Hsin-Fei
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物理研究所
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電機學院
Unlike organic field-effect transistor with accumulated channel at dielectric/semiconductor interface, vertical organic transistor exhibits bulk channel current and hence performs good bias stress reliability. Adding self-assemble-monolayer to treat vertical channel can further modulate the charge-trapping surrounding the base electrode and hence influence the bias stress reliability. During 4300-s positive/negative bias stresses, stable output current and on/off ratio are demonstrated by using octadecyltrichlorosilane (OTS)-passivated vertical channel. The good reliability together with the low operation voltage and the high output current make vertical organic transistors capable of driving organic light emitting diode. (C) 2014 Elsevier B.V. All rights reserved.
Achieving High Field-Effect Mobility in Amorphous Indium-Gallium-Zinc Oxide by Capping a Strong Reduction Layer
(2012-07-10)
Zan, Hsiao-Wen
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Yeh, Chun-Cheng
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Meng, Hsin-Fei
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Tsai, Chuang-Chuang
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Chen, Liang-Hao
Achieving saturation in vertical organic transistors for organic light-emitting diode driving by nanorod channel geometric control
(2013-04-22)
Li, Chang-Hung
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Stehlin, Fabrice
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Wang, Kai-Ruei
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Lin, Yu-Hsin
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Wieder, Fernand
When conventional field-effect transistors with short channel length suffer from non-saturated output characteristics, this work proposed a vertical channel transistor to operate like a solid-state vacuum tube and exhibit good saturated curves. We utilized deep ultra-violet interference lithography to produce ordered grid-like metal to control the potential profile in vertical channel. We compared experimental and simulated characteristics to investigate the keys to achieve saturation. Finally, with an optimized design, a vertical organic transistor is used to drive a solution-processed white-light organic light-emitting diode to perform a luminescence control (0-260 cd/m(2)) with a 3.3-V base potential swing. (C) 2013 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4802999]