Exploring the ultrasonic nozzle spray-coating technique for the fabrication of solution-processed organic electronics

Han, Singu,Jeong, Heejeong,Jang, Hayeong,Baek, Seolhee,Kim, Se Hyun,Lee, Hwa Sung ELSEVIER 2017 ORGANIC ELECTRONICS Vol.49 No.-

<P><B>Abstract</B></P> <P>The ultrasonic nozzle (US) spray method was investigated for its utility in fabricating organic electrodes composed of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), a standard conductive polymer material used to produce large-area low-cost OFETs. The US spray technique involves generating a solution spray by first passing the solution through a head and nozzle subjected to ultrasonic vibrations that induce atomization. This method is advantageous in that the resulting spray comprises extremely small solution droplets a few micrometers in diameter, unlike the spray produced using conventional air spray methods. The PEDOT:PSS US solution spraying process was optimized by controlling the flow rate of the N<SUB>2</SUB> carrier gas and the substrate temperature while monitoring the quality of the resulting PEDOT:PSS electrode films. The pentacene field-effect transistors prepared using the US spray method displayed a maximum field-effect mobility of 0.47 cm<SUP>2</SUP>V<SUP>−1</SUP>s<SUP>−1</SUP> (with an average value of 0.31 cm<SUP>2</SUP>V<SUP>−1</SUP>s<SUP>−1</SUP>), 35% better than the mobilities achieved using the conventional air spray method. In addition, the device-to-device reproducibility was improved, as indicated by a decrease in the standard deviation of the mobility values from 30% for the air spray devices to 24% for the US spray devices. These results indicated that the US spray technique is efficient and superior to the conventional air spray method for the development of low-cost large-area organic electronics.</P> <P><B>Highlights</B></P> <P> <UL> <LI> US spray method is investigated for printing organic PEDOT:PSS electrodes. </LI> <LI> Pentacene-FETs using US spray display 35% higher μ<SUB>FET</SUB> compared with conventional spray method. </LI> <LI> The mobility reproducibility is improved by a decrease of the standard deviation from 30% to 24%. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

2유체 노즐에서 초음파 에너지 부가 유체의 미립화 특성에 관한 기초연구

김명규,김태규,김유영 진주산업대학교 2001 산업과학기술연구소보 Vol.- No.8

This study investigated the effect of added ultrasonic energy on atomizing liquid in twin-fluid atomizers. For this purpose, variations in ultrasonic energy amount and atomizing air pressure were selected as variables in order to compare liquid flow rates, sauter mean diameters(SMD), and droplet distributions on the conventional spray and a ultrasonic-energy-added spray system. In results, The comparition of liquid flow rates on the conventional and ultrasonic-energy-added systems indicated that the latter system produced higher liquid flow rates that the former, and higher ultrasonic energy led to greater liquid flow rates, The sauter mean diameters were found to be significantly lower in the case of ultrasonic-energy-added spray than in the conventional spray at every level of atomizing air pressure, At every level of atomifing air pressure, the ultrasonic -energy-added spray system produced significantly more uniform droplet distribution than the conventional system.

압전체를 이용한 약품 분사용 초음파 분사 노즐 시스템

고재석,김용현,김형수,조순행,최승철 한국마이크로전자및패키징학회 2003 마이크로전자 및 패키징학회지 Vol.10 No.4

압전 세라믹스를 이용하여 약품 분사용 초음파분사 노즐을 제작하였다. 정수장의 혼화 공정에 사용되는 약품(응집제)의 고효율 분산을 위해 분사 노즐을 설계하였으며 압전세라믹을 최적화하였다. 제작된 초음파 약품 분사 노즐을 패키징하여 정수장의 약품 혼화 과정에 적용하여 약품사용의 고 효율화와 사용량 저감을 위한 연구를 진행하였다. 압전체는 실리콘으로 마감처리를 하였으며 Al으로 패키징하였다. 본 초음파 분사 노즐 시스템을 적용하여 혼화지에 실험한 결과 약품의 순간 혼화를 촉진시키는 기술로 투입 약품량을 저감시킬 수 있을 것으로 판단된다. 초음파 발진 약품 분사시, 무발진과 비교하여 대장균 제거 효율에서 현저하게 높아졌다. A new type of ultrasonic spray nozzle was fabricated employing a piezoelectric device. The spray nozzle was designed to disperse chemicals in a water treatment mixing tank. The piezoelectric properties in ultrasonic spray nozzles were optimized to improve the dispersion of chemicals. The piezoelectrics were packaged in an aluminum case with silicone resin for the aqueous solution proof packaging. Chemicals were dispersed with high efficiency and the chemicals consumption was reduced by the ultrasonic fine particle spraying. The concentration of Escherichia coli in mixing tank was decreased remarkably using ultrasonic spray nozzle dispersion compared to the conventional methods.

농업용 붐 분무기의 노즐 높이 및 분무 균일 성 측정을 위한 초음파 센서에 대한 온도의 영향

샤피크키라가 ( Shafik Kiraga ),레자나심 ( Md Nasim Reza ),초두리밀런 ( Milon Chowdhury ),이슬람나피울 ( Md Nafiul Islam ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.1

The increasing popularity of boom height controllers requires a desired nozzle height above the spray targets for effective spraying. The objective of this study was to determine the effect of temperature on nozzle height measurement using ultrasonic sensors and the impact on spray uniformity. Experiments were carried out with a constant nozzle spacing of 50 cm and a pressure of 600 kPa considering temperature compensation and non-compensation states of ultrasonic sensor measurements. Nozzle heights of 30, 50, and 70 cm were selected for reference. Two measurements were carried out for each selected height with a temperature compensated and non-compensated state at 15, 25, and 300C. The spray distribution was also determined for each measurements. Coefficient of Variation (CV) and percent measurement error (ME) were used to characterize spray uniformity and temperature effect on height measurement. The estimated heights with temperature compensation were closer to the reference heights, which exhibits a low ME. The ME increased from low to high temperatures. Temperature compensated heights resulted in more even spraying trends, with lower CV values accompanied by non-compensated heights. Our findings showed that, ultrasonic sensors need temperature correction for proper Nozzle height measurement and optimal spray distribution.

Crystal grain growth of planar type mixed halide perovskite film via ultrasonic spray coating

( Choi Seongyun ),김상수,임상혁 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

Recently, researchers are studying to resolve global warming challenges. Solar energy is a non-pollution, sustainable, abundant, and clean resource to resolve the problem. In the past few years, perovskite solar cells (PSCs) have been researched as promise next-generation solar cells due to its high efficiency, high-voltage, solution processibility, and direct bandgap. To manufacture PSCs efficiently, spray coating process is used for patterning and large-area coating. In addition to enhance the high performance of PSCs, large crystal is essential since PSCs mainly decompose in grain boundaries. Therefore, we investigated to increase the perovskite crystal grain by substituting metal halide CuBr2-complex using ultrasonic spray.

Slit-jet 노즐을 통과한 초음파 무화 에어로졸 화염에 정상초음파가 미치는 영향

안현종(Hyun Jong Ahn),강윤형(Yun Hyeong Kang),김정수(Jeong Soo Kim) 한국추진공학회 2020 한국추진공학회지 Vol.24 No.6

In liquid-fuel spray combustion, an experimental study was conducted to observe the effect of ultrasonic excitation on the ultrasonically-atomized liquid fuel flame by controlling pressure field through an ultrasonic standing wave. Flame of the ultrasonically-atomized kerosene aerosol was visualized by using a high speed camera, DSLR, and Schlieren photography. The amount of fuel consumed was obtained by a precise flow-rate measurement technique during combustion, through which the ratio of carrier gas (air) to fuel mass was able to be obtained, too. As a result, it could be found that the combustion reaction-rate of the liquid-fuel aerosol was increased by applying an ultrasonic standing wave to the secondary flame zone of the flame.

Ultrasonically sprayed-on perovskite solar cells-effects of organic cation on defect formation of CH3NH3PbI3 films

Nakorn Henjongchom,Nopporn Rujisamphan,Pisist Kumnorkaew,I-Ming Tang,Vittaya Amornkitbumrung,Thidarat Supasai 한국물리학회 2019 Current Applied Physics Vol.19 No.12

Methylammonium lead iodide (CH3NH3PbI3) based perovskite having low degrees of the disorder is of great interest for optoelectronic and photovoltaic applications. In this work, a layer of CH3NH3PbI3 was successfully prepared using an ultrasonically sprayed-nebulous method. Changes in structural and optical properties alongside with photo-induced charge separation and transportation behavior were systematically studied. The surface photovoltage spectra reveal a significant reduction of the density of deep defect states as the organic content was increased. It was observed that the measured values of Urbach energies decrease from 33.36 to 28.24 meV as the amount of organic content was increased to an optimum value. The best perovskite solar cells obtained using the sprayed-on approach exhibited a Jsc of 16.54 mA/cm2, a Voc of 0.99 V, and a FF of 62.4, resulting in an overall PCE of 10.09%.

고주파 진동자에 의해 미립화된 액체연료의 분무 연소특성 고찰을 위한 예비실험

김민성(Min Sung Kim),김정수(Jeong Soo Kim),배대석(Dae Seok Bae) 한국추진공학회 2015 한국추진공학회 학술대회논문집 Vol.2015 No.5

초음파 진동자에 의해 미립화된 탄화수소계 액체연료를 분사하는 연소기의 연소특성 고찰을 위한 예비 실험이 수행되었다. DSLR 카메라를 이용하여 액체연료의 분무 및 화염 형상을 획득하였으며, 이미지 후처리를 통해 그 구조를 상세히 분석하였다. 그 결과 slit형 노즐을 통해 분무되는 액체연료는 분사단면에서의 액적의 밀도가 균일하지 않으며, slit 끝단부로 편중되는 것을 확인하였다. 또한 화염과 분무의 상관관계를 고찰하였다. A preliminary experimental study was conducted to investigate the combustion characteristics of hydrocarbon liquid-fuel spray atomized ultrasonically. Configurations of the liquid-fuel spray and flame were caught by DSLR camera, and images were analyzed in detail through post-processing. As results, the fuel spray through a slit-shaped nozzle showed that the droplet density in the jet cross-section was not uniform. A similarity on the shape between the flame and spray was observed, too.

Sol-gel 하이브리드 용액을 이용한 반사방지막 제조

박종국,이지선,이미재,이영진,전대우,김진호,Park, Jong-Guk,Lee, Ji-Sun,Lee, Mi-Jai,Lee, Young Jin,Jeon, Dae-Woo,Kim, Jin-Ho 한국결정성장학회 2016 한국결정성장학회지 Vol.26 No.6

초음파 스프레이를 이용하여 유리기판 위에 반사방지 박막이 제조되었다. GPTMS와 TEOS는 솔-젤 하이브리드 코팅 용액을 제조하기 위하여 사용되었다. 반사방지막의 코팅 두께를 제어하기 위하여 스프레이 노즐의 이동속도는 15~25 mm/s로 변경되었다. 스프레이 노즐의 이동속도가 증가 됨에 따라 반사방지막의 두께는 138 nm에서 86 nm로 감소되었다. 20 mm/s의 노즐 이동속도에 의해 제조된 반사방지막의 굴절률은 약 1.31, 막의 두께는 104 nm이며, 380 nm에서 780 nm의 가시광 영역에서의 평균 반사율은 0.75 %, 투과율은 94 %로 측정되었다. Anti-reflection (AR) thin films were fabricated on a glass substrate by using an ultrasonic spray. Glycidoxypropyl trimethoxysilane (GPTMS) and tetraethyl orthosilicate (TEOS) were used to synthesize a sol-gel hybrid coating solution. The moving speed of spray nozzle was changed from 15~25 mm/s to control the coating thickness of AR thin film. As the moving speed of spray nozzle increased, the thickness of AR thin film decreased from 138 nm to 86 nm. When the AR thin film was fabricated by nozzle moving speed of 20 mm/s, the refractive index and thickness of AR thin film was measured to be 1.31 and 104 nm, respectively. The average reflectance and transmittance of AR thin film coating glass was measured to be 0.75 % and 94 %, respectively into the visible light range of 380~780 nm.

기상합성공정을 이용한 FePt 나노입자의 실시간 L10 상변화

이기우 ( Ki Woo Lee ),이창우 ( Chang Woo Lee ),김순길 ( Soon Gil Kim ),이재성 ( Jai Sung Lee ) 대한금속재료학회(구 대한금속학회) 2011 대한금속·재료학회지 Vol.49 No.1

Real-time formation of L10 phase of FePt nanoparticles in the gas phase during ultrasonic-spray pyrolysis is first discussed in the present study. Without any post heat treatment, L10 phase of FePt nanoparticles appeared at the temperature above 900℃ in the gas phase synthesis. X-ray diffractometry (XRD) and transmission electron microscopy (TEM) studies revealed that FePt nanoparticles less than 10 nm in size contained small volume of L10 fct phase. However, in other samples obtained at the temperature below 900℃, iron oxide phase co-existed and no evidence of phase transformation was found. Thus, it is anticipated that the time of flight of particles required for crystallization and phase transformation was extended according to the increase of the collision rate. Finally, magnetic properties represented by coercivity and saturation magnetization and functional groups on the particle surface were discussed based on VSM and FTIR results.