디스플레이

In this paper, we demonstrate the use of polymer dispersed liquid crystal (PDLC) imprinted with a microlens array (MLA) via solution process to improve the outcoupling efficiency of organic light emitting diodes (OLEDs). The PDLC, well known for its scattering effect, is an excellent technology for improving the outcoupling efficiency of OLEDs. Additionally, we introduce a simple spin-coating process to fabricate PDLC which is adaptable for future solution-processed OLEDs. The MLA-imprinted PDLC applied OLED shows an enhancement factor of 1.22 in outcoupling efficiency which is a 37.5% increase compared to the existing PDLC techniques without changing the electrical properties of the OLED. Through this approach, we can expect the roll-to-roll based extremely flexible OLED, and with further research on pattering PDLC by various templates, higher outcoupling efficiency is achievable through a simple UV irradiation process.

Poly-dichloro-para-xylylene (parylene-C) film is formed through a chemical vapor deposition process, where monomeric gases are polymerized on the target surface at room temperature and are used as transparent insulating coating films. The thin parylene-C films exhibit uniform conformal layers even when deposited on substrates or surfaces with fine cracks, structures, and bumps. However, the film is highly transparent in the visible range (transmittance > 90%); thus, it is difficult to visually identify, inspect the coating process and check for any defects when used as an insulation film. Some reports have demonstrated the deposition of visible (hazy) parylene films through the control of the vaporization or pyrolysis of the parylene-C powder and sublimed dimers, respectively. Even though these films have been applied as device substrates and light extraction layers in organic light-emitting diodes (OLEDs), their optical and electrical aracteristics have not been extensively explored, especially for their applications as insulation coatings. In this study, the characteristics of visible parylene films produced by tuning the ratio of dimer to monomer gases via the adjustments of the pyrolysis temperature are analyzed with electrical and optical methods. Parylene-C films deposited within the pyrolysis temperature of 400–700 ◦ C exhibited a haze range of 10–90%. A relative reflectance of 18.8% at 550 nm of the visible light region was achieved in the visible parylene film deposited with a pyrolysis temperature of 400 ◦ C. Resistivity in the order of 1010 Ω cm was achieved for the visible parylene films measured with the transmission line measurement (TLM) method. The films can be applied in advanced insulation coatings for various optical systems and electronic devices.

In this paper, we propose a single-layer thin-film color glass manufacturing process for building-integrated photovoltaics (BIPV) with excellent aesthetics and high transmittance, through a solution process using pearlescent pigments. As a matrix for the color solution, ethylene vinyl acetate (EVA), which serves as an encapsulant and adhesive for the photovoltaic module (PV), was dissolved and used as a matrix for the color solution. The color glass produced is excellent in securing the aesthetics of buildings, has a high transmittance of 90% or more, outputs a maximum solar power generation efficiency of 91% from a solar cell, and can minimize the deterioration of power generation efficiency. In addition, the characteristics do not change over time, so it is suitable as color glass for BIPV. Through this study, the solution-based color glass manufacturing process for BIPV using dissolved EVA as a matrix forms a single-layer thin film with good color extensions. The choice of EVA as a matrix makes it possible for color glass to be easily attached to a solar panel using a heat press method. This proposed technique makes it easier and simpler to manufacture color glass as compared to the physical vapor deposition process. The adoption of this solution process technique to fabricate pearlescent pigment-based color glass can effectively reduce the time and cost of the process, so it is expected to be applied to the low-cost BIPV market with excellent aesthetics and high transmittance.

In this study, we propose a solution process for realizing colored glass for building integrated photovoltaic (BIPV) systems by spin coating a color solution composed of pearlescent pigments mixed in a Norland Optical Adhesive (NOA) matrix. Color solutions are made from mixing pearlescent pigments in NOA63. Compared to a physical vapor deposition process, color coatings are achieved by spin coating in a relatively simple and inexpensive process at room temperature. The optical properties can be easily controlled by adjusting the spin coating speed and the concentration of the pearlescent pigments. The produced colored glass achieved a high transmittance of 85% or more in the visible wavelength range, except for the wavelength spectrum exhibiting the maximum reflectance. In addition, we propose a one-step lamination process of colored glass on a solar cell by leveraging on the adhesive property of the NOA matrix. This eliminates the cost and process of additional ethylene vinyl acetate (EVA) layer or other materials used in the conventional lamination process. The colored glass produced through this study has stability that does not change its properties over time. Therefore, it is expected to be applied to the BIPV solar module market where aesthetics and energy efficiency are required.

The charge trapping property of spin-coated perhydropolysilazane (PHPS) layers for solution-processed organic and oxide thin film memory transistors is demonstrated. The nitrogen content within the PHPS layer is decreased by increasing the annealing temperatures from room temperature to 450 °C. The PHPS layer added to the SiO2 gate insulator in the charge trap memories (CTMs) shows good memory functionalities which are electrically programmable, and is erased either electrically or optically depending on the semiconductor used. The stored or erased charges in the p-type semiconductor-based CTM result in relatively large threshold voltage shifts (∆VTH > 60 V) and large memory on- and off-current ratio (IM,ON/IM,OFF > 103) with the respective memory output current extrapolated to 108 s. The n-type CTM shows ∆VTH ≈ 20 V, IM,ON/IM,OFF of 0.5 × 103 and is extrapolated to 10 15 s. It is concluded that the origin of the charge-traps in both the p-type and n-type CTMs mainly originates from the PHPS charge trap layer (CTL) and greatly occurs in highly concentrated nitrogen PHPS layers. There is a high possibility of using the PHPS CTL in a wide variety of cost-effective CTMs even with high temperature processed semiconductors.

The stable multibit storage operation of solution-processed organic nonvolatile memories (ONVMs) based on ferroelectric field-effect transistors (FeFETs) for high density data storage devices are demonstrated. The proposed multibit ONVM structure consists of a p-type polymer semiconductor sandwiched between poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] layers serving as ferroelectric gate insulators to form a dual gate ferroelectric–ferroelectric memory transistor (DG Fe-FeMT). With the extra memory space created by the spatially separated ferroelectrics, a 2-bit memory representation (“11”, “10”, “01” and “00”) with clear memory margins is achieved due to the bistability of each P(VDF-TrFE) and the high performance of the polymer semiconductor. The distinct four-level reading of memory output currents (IM,OUTs) results from the independent programming voltages of the dual gates. An excellent distinct six-level IM,OUTs are also achieved in DG Fe-FeMT using the intermediate programming voltages. Finally, the possibility of 3−bit, or 8 memory states, are demonstrated by optimizing the bistability and intermediate polarization states of the ferroelectrics without increasing the device area horizontally. The DG Fe-FeMT has a great potential for cost−effective flexible nonvolatile multibit data storage devices due to its solution-process and low annealing temperatures.

Investigation of the long-term stability of charge generation layers (CGLs) provides a fundamental and an essential approach in achieving highly efficient tandem organic electronic devices. Thus, in this foremost study, the degradation mechanism of electrically aged organic p-n heterojunction CGLs has been investigated by impedance and optical spectroscopy. Rubidium carbonate (Rb2CO3)edoped 2,2,2-(1,3,5- benzinetriyl)-tris(1-phenyl-1H-benzimidazole) (TPBi) and molybdenum trioxide (MoO3)edoped 1,4-bis [N-(1-naphthyl)-N0 -phenylamino]-4,40 -diamine (NPB) are used as the n-type and p-type organic semiconductors, respectively. A detailed analysis from capacitance-frequency (CeF) and capacitance-voltage (CeV) characteristics reveals reduced charge generation and 19.6% reduction in the geometric capacitance of the CGL after electrical aging. Reduced peak intensity from UVeViseNIR spectra of the aged CGL points to 21.4% charge transfer complex decomposition of the Rb2CO3-doped TPBi. We propose that the rate-limiting step of charge generation in the CGL is caused by the electron transport in the TPBi:Rb2CO3 layer and not the charge generation itself at the TPBi:Rb2CO3/NPB:MoO3 heterojunction. This simple, comprehensive, and non-destructive technique facilitates a crucial analysis that underpins the mechanism of device degradation and further provides a fundamental approach in developing highly stable CGLs for efficient organic electronic devices.

This study proposes front colored glass for building integrated photovoltaic (BIPV) systems based on multi-layered derivatives of glass/MoO3 /Al2 O3 with a process technology developed to realize it. Molybdenum oxide (MoO3 ) and aluminum oxide (Al2 O3 ) layers are selected as suitable candidates to achieve thin multi-layer color films, owing to the large difference in their refractive indices. We first investigated from a simulation based on wave optics that the glass/MoO3 /Al2 O3 multi-layer type offers more color design freedom and a cheaper fabrication process when compared to the glass/Al2 O3 /MoO3 multi-layer type. Based on the simulation, bright blue and green were primarily fabricated on glass. It is further demonstrated that brighter colors, such as yellow and pink, can be achieved secondarily with glass/MoO3 /Al2 O3 /MoO3 due to enhanced multi-interfacial reflections. The fabricated color glasses showed the desired optical properties with a maximum transmittance exceeding 80%. This technology exhibits promising potential in commercial BIPV system applications.

We demonstrated the effect of a buffer layer on the electrical characteristics of ferroelectric polymer capacitors and field-effect transistors. Various polymer materials with a dielectric constant between 2 and 42 were used to form buffer layers with a similar thicknesses, but with different capacitances. In order to evaluate the characteristics of the ferroelectrics with a buffer layer, the polarization–voltage characteristics of the capacitor, the transfer characteristics, and the retention characteristics of the transistors were investigated. As the capacitance of the buffer layer increased, high remnant polarization (Pr), high hysteresis, and long retention times were observed. Exceptionally, when poly(methylmethacrylate) and rigid poly(aryl ether) (poly(9,9-bis(4-hydroxyphenyl)fluorene-co-decafluorobiphenyl)) were used as the buffer layer, Pr had a value close to 0 in the dynamic measurement polarization–voltage (P–V) characteristic, but the quasi-static measurement transfer characteristic and the static measurement retention characteristic showed relatively high hysteresis and long retention times. Our study provides a scientific and technical basis for the design of ferroelectric memory and neuromorphic devices.

Here, a stretchable organic field-effect transistor (OFET) that exhibits constant electrical performance irrespective of the strain direction is demonstrated. The device is integrated onto an elastomer template with randomly oriented wrinkles on its surface; these wrinkles are spontaneously formed because of the differences in the thermal–mechanical properties of the plastic layer and the underlying elastomer. To achieve this microtopography, a relatively hard polymer, Parylene C, is ad-deposited onto an elastomer blended with polydimethylsiloxane and Ecoflex, resulting in PD-flex. Consequently, this microtopography offers stable device operations of a dinaphtho[2,3-b:2′,3′-f  ]thieno[3,2-b]thiophene OFET array under 5% elongation irrespective of strain direction. Furthermore, the electrical performance is highly stable during 10 000 cycles of uniaxial strain, as verified by negligible modulation of the device's field-effect mobility, threshold voltage, and drain-current maximum. This approach allows nonstretchable device components to be relevant to stretchable electronics. More importantly, it is highly compatible to device alignment and provides stability under various kinds of mechanical deformations.

Moisture in industrial gas affects the quality of products, and thus, studies on the water desorption behaviours of the components are necessary for industries to keep their gas distribution system extremely dry. In this study, the water desorption characteristics of a gas filter was evaluated, when it was newly installed in a setup operating in the trace-moisture regime. The desorption kinetics of the water based on the Arrhenius equation was utilized for analysing the experimental observations. The characteristics of water desorption from the filter were examined under a dried N-2 gas flow with varying environmental conditions, such as temperature, pressure, flow rate and preconditioning relative humidity. For practical applications, a drying time of the filter, taken until the water vapour fraction reaches a target concentration (10 nmol center dot mol(-1)), was measured under varying conditions. Finally, the uncertainty budget on the drying time was evaluated. The findings of this study provide a practical insight on the water desorption behaviour, which would be useful for maintaining dry gas supply lines.

We investigated layered titanium nitride (TiN) and aluminum nitride (AlN) for color glasses in building integrated photovoltaic (BIPV) systems. AlN and TiN are among suitable and cost-effective optical materials to be used as thin multilayer films, owing to the significant difference in their refractive index. To fabricate the structure, we used radio frequency magnetron deposition method to achieve the target thickness uniformly. A simple, fast, and cheap fabrication method is achieved by depositing the multilayer films in a single sputtering chamber. It is demonstrated that a multilayer stack that allows light to be transmitted from a low refractive index layer to a high refractive index layer or vice-versa can effectively create various distinct color reflections for different film thicknesses and multilayer structures. It is investigated from simulation based on wave optics that TiN/AlN multilayer offers better color design freedom and a cheaper fabrication process as compared to AlN/TiN multilayer films. Blue, green, and yellow color glasses with optical transmittance of more than 80% was achieved by indium tin oxide (ITO)-coated glass/TiN/AlN multilayer films. This technology exhibits good potential in commercial BIPV system applications.

This study investigates the applications of 3D printing technology in the wiring process used in the field of electronic packaging. A Cu wiring process is developed to replace the expensive Ag-based alternative primarily used in commercial 3D electronic circuit printing as per industry standards. The substrates needed for our experiments are developed using a 3D printer assembled prior to the research, through which poly-ether-ether-ketone (PEEK) proves to be a high-strength, high heat-resistance material capable of undergoing the packaging process. The Cu wiring process is performed via laser sintering in ambient condition using a Cu micro/nanoparticle paste. Adopting this method minimizes the cost and duration of the process without relying on inert atmosphere generation. The optimum laser sintering condition for the Cu paste is found to be two consecutive scans at 20 W. Energy dispersive X-ray spectroscopy (EDS) measurements show that the oxidation of the surface is about 1.35%, and further oxidation is prevented through epoxy molding. The touch sensor by Cu wiring module operate optimally even a month after its manufacture. 3D printing technology proves to be capable of replacing the wiring process used for electronic packaging.

We have investigated an effective and a single-step chemical vapor deposition (CVD) method to achieve conformal visible poly-dichloro-para-xylylene (parylene C) film for light extraction enhancement in bottom-emitting organic light-emitting diodes (OLEDs) at room temperature. We report that sublimed parylene dimers pyrolyzed between 400 degrees C and 500 degrees C resulted in visible parylene films with tunable transmittance and haze, exhibiting light scattering properties due to the formation of uniformly distributed dimer crystals. We achieved a novel conformal visible parylene film with total transmittance and high haze of 79.5% and 93.6%, respectively. It is observed that the outcoupling efficiency of the OLEDs employing the visible parylene film is enhanced up to 45.8%. Additionally, the OLED with the visible parylene light extraction film shows limited angle-dependency of emission spectrum over viewing angles. The single-step room temperature fabrication process of this conformal outcoupling film paves the way to achieving commercial high-performance OLEDs. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

We suggest a facile method to reduce the surface roughness of the ferroelectric polymer insulator to enhance the electrical performance of the ferroelectric field effect memory transistors (FeFET). Ferroelectric-dielectric mixed buffer layer was used to reduce the high surface roughness of the single layer ferroelectric polymer insulator. The FeFET with mixed buffer bilayer (BL-FeFET) showed more than 25 times higher on-current (3.40 mu A) compared with single layer FeFET (130 nA). The BL-FeFET showed enhanced memory retention, higher memory on-off ratio than the conventional single layer FeFET (SL-FeFET). The enhancement of the electrical performance of the BL-FeFET can be attributed to the smoothening of the rough needle-like grain surface morphology of the ferroelectric polymer insulator in the SL-FeFET. This process of mixed buffer polymer insulator may provide a technological method for production of high-performance nonvolatile FeFET memory devices.

Flexible strain sensors are recognized as a key component of electronic-skin technology. One of the important features for strain sensors is that they should be able to sensitively recognize the direction of the external stress to accurately detect the various motions of humans or matter. Herein, we successfully developed a directionally responsive piezoresistive strain sensor with asterisk-shaped CNT sensing electrodes to recognize the direction of an applied external stress, thereby overcoming some of the shortcomings of established sensors. Under 5% strain, the change in relative resistance of the sensor developed here differed by up to a factor of 24.5 for different orientations of the sensor electrode relative to the source of the stress, i.e., a high angular dependence of the sensing performance on the external stress direction was observed. In particular, the asterisk-shaped CNT strain sensors showed a super-linear relationship between response and strain for low strains of up to 5%, allowing them to provide a good sensing platform for recognizing micro-deformations. Finally, we demonstrated that our sensor could recognize the direction of the movement of an applied brush and the magnitude and direction of the tilt of a home-built joystick attached onto the sensor device.

We demonstrated the enhancement of the retention characteristics in solution-processed ferroelectric memory transistors. For enhanced retention characteristics, solution-processed Indium Gallium Zinc Oxide (InGaZnO) semiconductor is used as an active layer in a dual-gate structure to achieve high memory on-current and low memory off-current respectively. In our dual-gate oxide ferroelectric thin-film transistor (DG Ox-FeTFT), while conventional TFT characteristic is observed during bottom-gate sweeping, large hysteresis is exhibited during top-gate sweeping with high memory on-current due to the high mobility of the InGaZnO. The voltage applied to the counter bottom-gate electrode causes variations in the turn-on voltage position, which controlled the memory on- and off-current in retention characteristics. Specifically, due to the full depletion of semiconductor by the high negative counter gate bias, the memory off-current in reading operation is dramatically reduced by 10(4). The application of "a high negative counter field to the dual-gate solution-processed ferroelectric memory gives a high memory on- and off-current ratio useful for the production of high performance multi-bit memory devices.

Random Al2O3 nanoparticle-based polymer composite films are investigated as external scattering layers to enhance light extraction from flexible organic light-emitting diodes (OLEDs). We found that the size and concentration of the nanoparticles (NPs) in the polymer film play a crucial role in improving light extraction. It turned out that their increase has a favorable impact on the light output of the devices, as the high concentration of the NPs leads to the formation of large nanoparticle clusters, which, in turn, yield pore-containing films. As a result, light extraction efficiency of the flexible OLEDs on PEN substrates was enhanced by a factor of 1.65 by the incorporation of the scattering layer, with the highest Al2O3 NP concentration of 99 wt%. This outcome is attributed to the reduction of the waveguide mode and total internal reflection at the substrate/air interface induced by the randomly distributed NPs in the flexible scattering layer. Our work demonstrates an efficient, solution-processable, and low-cost light-outcoupling structure for large-area and flexible OLED applications. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

본 논문에서는 라즈베리파이 카메라와 함수 발생기를 활용하여 이미지에서 휘도를 분석하고 이를 바탕으로 전압을 인가하여 스마트 윈도우에 착색을 통해 광 투과를 조절할 수 있는 자동화 시스템을 제안한다. 기존 휘도 측정에 사용되는 휘도계는 가격대가 높고 사용자의 불필요한 움직임을 요구해 실생활에서 활용하기 어렵다. 그러나 사진 촬영 후 Python Open Source Computer Vision Library (OpenCV)를 활용한 이미지에서의 휘도 분석은 저렴하고 휴대가 간편하여 실생활에서 쉽게 응용할 수 있다. 이 시스템을 스마트 윈도우가 적용된 환경에 사용하여 창호의 휘도를 검출하였다. 이미지의 휘도를 바탕으로 스마트 윈도우의 착색 조절을 통해 창호의 휘도를 감소시켜 재실자는 쾌적한 시 환경을 구축할 수 있다.

본 연구에서는 액정에 인가되는 전압을 조절하여 편광을 조절할 수 있는 액정 기반 편광 조절 기술을 폐쇄회로 텔 레비전(CCTV)에 적용하여 사용자가 원하는 각도의 편광만을 투과시킬 수 있는 시스템을 제안한다. 기존의 편광필름이 적용된 CCTV는 역광 보정 기능에 치중되어 있기 때문에 편광을 제어할 수 없어 수면에서 반사된 빛이나 차량에서 반사된 하이라이트가 피사체 식별을 방해한다. 그러나 Vertical Alignment 모드를 사용하면 전기적으로 편광을 조절할 수 있기 때문에 사용자가 원하는 각도의 편광만 투과시켜 반사되는 하이라이트를 제거할 수 있다. 이 기술을 사용하여 얻은 이미지들은 컴퓨터 소프트웨어에 의해 최적의 이미지로 도출하였다. 편광 각도와 투과율, 편광속도를 전기적으로 제어할 수 있는 액정 편광 패널을 편광 폐쇄회로 텔레비전에 적용하여 기존 CCTV에서의 피사체 식별을 개선하였다.

본 논문에서는 컬러 용액을 사용하여 스핀 코팅 방식으로 Building Integrated Photovoltaic(BIPV) 시스템용 전면 컬러 유리를 구현하였다. 컬러 유리 구현을 위해 진주광택 안료와 다양한 용액를 사용하여 컬러 용액에 적합한 용액을 조사하였다. 조사한 용액 중 자외선 광 경화제인 NOA series의 경우 다른 용액보다 우수한 코팅성과 컬러 재현성을 가진 컬러 유리를 구현할 수 있었다. NOA 65 기반의 컬러 용액으로 스핀 코팅하여 구현한 컬러 유리는 가시광선 및 근적외선 파장 대역에서 최대 86%의 높은 투과율 을 보였으며 시간에 따른 컬러 유리의 광학적 특성의 변화가 미미하여 BIPV용 컬러 유리 구현을 위한 컬러 용액으로 적합하였다. 스핀 코팅 방식을 활용한 용액 공정 방식은 기존의 물리적 증착 방식이나 나노 입자를 활용한 컬러 유리 제작 공정보다 쉽고 빠르게 컬러 유리를 제작할 수 있어 BIPV용 전면 컬러 유리 제작 공정이 용이해질 것으로 기대된다.

Humidity is an important physical quantity that is closely related with the quality of everyday life as well as the quality control of products in various industries. Here, we have developed a divided-flow type humidity generator of which humidity generation is faster than the saturator-based humidity generator in ppm level. The operation principle of the divided-flow humidity generator is first introduced. Then, the performance of the divided-flow humidity generator is verified by testing the radiosonde humidity sensor at low temperature. As a result, the humidity generated from the divided-flow humidity generator is consistent with the saturator-based precision humidity generator within 1.6% relative humidity in the range from 10% to 40% at -45oC. It is also found that the radiosonde humidity sensor shows measurement errors by 3% - 5% at -45oC when it is only calibrated at room temperature. The response times of radiosonde humidity sensor using the divided-flow humidity generator are between about 2 and 9 minutes, whereas those by the saturatorbased humidity generator are about 20 minutes. In this regard, the divided-flow humidity generator has a merit in terms of fast humidity changes for the calibration of radiosonde humidity sensors at low-temperatures.

본 연구에서는 영상감시 장치에 액정 기반 편광 제어 기술을 결합하여 피사체에서 반사된 빛의 부분 선형 편광을 제거할 수 있는편광 영상감치 장치 시스템을 제안한다. 빛의 편광 방향을 전기 광학적으로 변조하는 TN(Twisted Nematic) 액정을 사용하면 카메라 렌즈 앞에서 편광 필터를 기계적으로 회전할 필요가 없다. 이러한 기술을 사용하여 얻은 여러 편광 이미지는 컴퓨터 소프트웨어에 의해 이미지화된다. 또한 액정 패널은 사각형 형태로 생산되어 왔으나 대부분의 카메라 렌즈는 일반적으로 원형이고 렌즈 주변에조명이나 기타 구동 장치가 설치되어 있어 원형 액정 패널을 적용하여 공간을 최적화하였다. 이 기술의 개발을 통해 전기적으로 전환 가능하고 공간에 최적화된 액정 편광 패널이 개발되었다.

We investigated light extraction film based on polymer dispersed liquid crystal (PDLC) for application inorganic light emitting diodes (OLEDs). At least 30 seconds of direct UV irradiation process for curing PDLC filmon a bottom-emitting OLEDs was successfully achieved without damage on the intrinsic properties of the OLED.We demonstrated that high haze and transmittance can be tuned simultaneously by controlling the UV curingtime. By adding PDLC as an external layer without any additional treatment, the light scattering and extractionis increased. Consequently, a PDLC scattering film with 89.8% and 59.9 of total transmittance and hazerespectively, achieved about 16% of light intensity enhancement from integrating sphere measurement.

이 논문에서는 전이 금속 산화물(TMO)층으로 구성된 다층 박막을 사용하는 BIPV(Building Integrated Photovoltaic)시스템용 전면 컬러 유리를 제안하였다. 몰리브덴 산화물(MoO3) 및 텅스텐 산화물(WO3)은 굴절률 차이가 큰 계면을형성하여 적절한 간섭효과를 얻을 수 있다. 단일 Thermal Evaporator 증착 방법을 통해 다층 박막을 제작함으로써 간단하고 빠르며 저렴한 제조 방법을 제안하였다. MoO3(60nm)/WO3(100nm) 다층 박막으로 90% 이상의 광 투과율을 갖는 자홍색 유리를 시연하였으며, 이 기술은 상용화된 BIPV 시스템에 유용할 것으로 기대된다

Poly-para-xylylene C (Parylene C) and Aluminium Nitride (AlN) multilayered thin films using a single chamber are proposed to achieve transparent passivation for organic light-emitting diodes (OLED). Parylene C-AlN multilayered thin films were obtained through a sequential deposition of Parylene C layers by an optimized chemical vapor deposition as well as deposition of AlN layers by radio frequency reactive sputtering within a short process time at room temperature. An OLED passivated with the thin film showed a significant extension of shelf-life of 400 h at 25 degrees C and 30% RH without any formation of dark spots during the shelf-life analysis, while a reference OLED without any passivation film was degraded within 24 h. In addition, the multilayered passivation films exhibited considerable optical transparency with transmittance greater than 85% in the visible range. This result demonstrates that Parylene C-AlN multilayered films can be successfully deposited within a short time at room temperature in a single chamber for passivation applications in transparent flexible OLEDs and other organic electronic devices.