• 한국광학회지
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• 제29권6호
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• pp.262-267
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• 2018

본 논문에서는 유기발광다이오드 디스플레이(OLED)의 광 효율을 향상시키기 위해 방사방지필름을 새롭게 디자인하였다. 현재 상용화되고 있는 편광판의 편광도와 투과율을 변화시켜 OLED 반사방지필름에 사용하였을 경우 정면과 측면방향의 반사특성을 계산하였다. 그 결과 편광도가 99.995%나 99.990%인 상용화된 편광판의 편광도를 99.9% 수준으로 떨어뜨릴 경우, 반사방지필름의 평균 시감반사율은 사람의 눈으로 알아차리기 힘든 약 0.1% (증가율 환산 2.5%) 상승한 반면, 투과율은 기존보다 약 1.63~3.34%(증가율 환산 4.2~8.2%) 상승하였다. 이 결과는 기존 OLED에서 저반사율을 유지하면서 광효율을 상승시킬 수 있는 광학설계 조건을 제시하였다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.110.2-110.2
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• 2012

We reported on antireflective ZnSnO (ZTO)/Ag bilayer and ZTO/Ag/ZTO trilayer source/drain (S/D) electrodes for all-transparent ZTO channel based thin film transistors (TFTs). The ZTO/Ag bilayer is more transparent (83.71%) and effective source/drain (S/D) electrodes for the ZTO channel/Al2O3 gate dielectric/ITO gate electrode/glass structure than ZTO/Ag/ZTO trilayer because the bottom ZTO layer in the trilayer increasea contact resistance between S/D electrodes and ZTO channel layer and reduce the antireflection effect. The ZTO based all-transparent TFTs with ZTO/Ag bilayer S/D electrode showed a saturation mobility of 4.54cm2/Vs and switching property (1.31V/decade) comparable to TTFT with Ag S/D electrodes.

• 한국세라믹학회지
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• 제32권5호
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• pp.617-625
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• 1995

In order to reduce reflectance of soda-lime glass having average reflectance of 7.35% and refractive index of 1.53, single (SiO2), double (SiO2/20SiO2-80ZrO2), and triple (SiO2/ZrO2/75SiO2-25ZrO2) layers were designed and fabricated on the glass substrate by Sol-Gel method. Stble sols of SiO2-ZrO2 binary system for antireflective (AR) coatings were synthesized with tetraethyl orthosilicate (TEOS) and zirconium n-butoxide as precursors and ethylacetoacetate (EAcAc) as a chelating agent in an atmosphere environment. Films were deposited on soda-lime glass at the withdrawal rates of 3~11 cm/min using the prepared polymeric sols by dip-coating and they were heat-treated at 45$0^{\circ}C$ for 10 min to obtain homogeneous, amorphous and crack-free films. In case of SiO2-ZrO2 binary system, refractive index of film increased with an increase of ZrO2 mol%. Designed optical constant of films could be obtained through varying the withdrawal rate. In the visible region (380~780nm), reflectance was measured with UV/VIS/NIR Spectrophotometer. Average reflectances of the prepared single-layer [SiO2 (n=1.46, t=103nm)], double-layer [SiO2 (n=1.46, t=1-4nm)/20SiO2-80ZrO2 (n=1.81, t=82nm)], and triple-layer [SiO2 (n=1.46, t=104nm)/ZrO2 (n=1.90, t=80nm)/75SiO2-25ZrO2 (n=1.61, t=94 nm)] were 4.74%, 0.75% and 0.38%, respectively.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1996년도 재료학회 춘계학술발표회
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• pp.40-40
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• 1996

• 한국세라믹학회지
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• 제30권9호
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• pp.775-783
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• 1993

TiO2-SiO2 system anti-reflective(AR) film was prepared to decrease reflectance on the glass surface. The experiments were carried out as fellow, 1) preparation & hydrolysis of TiO2-SiO2 system sols. 2) glass dipping, and 3) drying & heat treatment. We investigated the refractive index and thickness of film with viscosity, zeta-potential of sol, sol concentration, withdrawal speed, drying and heat treatment condition. As a result, we prepared good qualitative Quarter-Half-Quarter type anti-reflective film that had minimum, 0.02% and average reflectance, 0.087% in the visible region.

• 한국진공학회지
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• 제19권2호
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• pp.81-90
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• 2010

층과 층 사이의 정전기적인력, 수소결합 또는 공유결합을 이용하여 층당 두께를 수 옹스트롱에서부터 수십 나노미터까지 제조할 수 있으며 박막의 표면 형태를 흡착시키고자 하는 물질 및 박막 후처리 공정을 통해 제어할 수 있으며 더 나아가, 삽입하는 물질의 특성에 따라 박막의 기능성을 집적화 및 다양화시킬 수 있다. 본 연구에서는 이러한 층상자기조립방법의 특성을 이용하여 반사방지막, 초소수성 필름 및 전기화학센서로의 응용가능성을 제시하였다. 반사방지막의 경우, 구형의 블록공중합체를 유리기판 위에 다층박막으로 적층시킴으로써 박막 굴절률을 1.25까지 감소시켰고 이를 통해 약 99.5%의 빛 투과도를 달성할 수 있었다. 더 나아가 바이오물질인 엔자임을 다층박막에 삽입시킬 경우, 활성 산소를 분해시키는 전기화학센서로의 제조가 가능함을 보인다. 본 연구는 본인이 이미 발표한 논문(J. Am. Chem. Soc. 128, 9935 (2006); Adv. Mater. 19, 4364 (2007); Electro. Mater. Lett. 3, 163 (2007))들을 정리하여 층상자기조립법에 관해 소개하는 논문이다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.393-393
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• 2012

Optically active nanostructures such as subwavelength moth-eye antireflective structures or surface enhanced Raman spectroscopy (SERS) active structures have been demonstrated to provide the effective suppression of unwanted reflections as in subwavelength structure (SWS) or effective enhancement of selective signals as in SERS. While various nanopatterning techniques such as photolithography, electron-beam lithography, wafer level nanoimprinting lithography, and interference lithography can be employed to fabricate these nanostructures, roll-to-roll (R2R) nanoimprinting is gaining interests due to its low cost, continuous, and scalable process. R2R nanoimprinting requires a master to produce a stamp that can be wrapped around a quartz roller for repeated nanoimprinting process. Among many possibilities, two different types of mask can be employed to fabricate optically active nanostructures. One is self-assembled Au nanoparticles on Si substrate by depositing Au film with sputtering followed by annealing process. The other is monolayer silica particles dissolved in ethanol spread on the wafer by spin-coating method. The process is optimized by considering the density of Au and silica nano particles, depth and shape of the patterns. The depth of the pattern can be controlled with dry etch process using reactive ion etching (RIE) with the mixture of SF6 and CHF3. The resultant nanostructures are characterized for their reflectance using UV-Vis-NIR spectrophotometer (Agilent technology, Cary 5000) and for surface morphology using scanning electron microscope (SEM, JEOL JSM-7100F). Once optimized, these optically active nanostructures can be used to replicate with roll-to-roll process or soft lithography for various applications including displays, solar cells, and biosensors.

• Journal of Ceramic Processing Research
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• 제19권6호
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• pp.525-529
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• 2018

The antireflective (AR) coated poly methyl methacrylate (PMMA) substrate was deposited by atomic layer deposition (ALD) on a self-assembled monolayer (SAM) to improve hydrophobicity and mechano-chemical properties of organic thin films. The water contact angles (WCA) were tested to characterize the surface wettability of SAM octadecyltrichlorosilane (OTS) films. Results showed that a contact angle of $105.9^{\circ}$ was obtained for the SAM films with an annealing process, and the highest WCA of $120^{\circ}$ was achieved for the films prepared by the SAM and ALD multi-process. The surface morphology of the SAM films with different assembly times and varying number of ALD cycles was obtained by atomic force microscopy (AFM). The maximum light transmittance for the SAM films on the PMMA substrate reached 99.9% at a wavelength of 450 nm. It was found that the SAM surfaces were not affected at all by the ALD process.

• 한국정보통신학회논문지
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• 제24권10호
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• pp.1306-1311
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• 2020

본 연구에서는 Ni cluster를 이용하여 제작된 나노 구조체를 반사방지막으로 활용하여 비가시광 UV 광통신용 신호 수신단에 적용 가능한 AlGaN 광다이오드의 성능을 개선하는 구조를 제안하였다. 반사방지막의 제작은 SiO2 위에 Ni cluster를 형성한 후 SiO2를 부분적으로 식각하는 방식으로 제조하였다. 반사방지막이 적용된 샘플은 반사방지막이 없는 구조의 샘플에 비해 상대적으로 작아진 반사도를 보였으며 나노구조체가 없는 SiO2 가 증착된 구조에 비해서 입사 광파장의 변화에 대해 균일한 반사도를 보였다. 최종적으로 2 nm 두께의 Ni 층을 열처리하여 제작된 Ni cluster를 이용한 반사방지막을 적용하여 UV 광다이오드를 제작하였고, 그 결과 SiO2 단일막을 가진 센서에 비해 240 nm에서 270 nm 파장영역에서 개선된 광반응도를 보였다.

• 한국전기전자재료학회논문지
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• 제32권4호
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• pp.281-286
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• 2019

Raman spectra of a-C:H thin films deposited with an unbalanced magnetron sputtering system showed that the G peak shifted to a higher wavenumber as the target power density increased and $I_D/I_G$ ratio increased from 0.902 to 1.012. Moreover, the transmittance of a-C:H films fabricated at 60 nm tended to decrease with increasing target power density; at 550 nm in the visible light region, the transmittance decreased from 69% to 58%. The rms surface roughness values of the a-C:H thin films decreased with increasing target power density, and varied from 1.11 nm to 0.71 nm. In order to achieve efficient light trapping, the light scattering at the rough interface must be enhanced. Consequently, the surface roughness of the thin film will decrease with the target power density. Further, the refractive index and reflectivity of the a-C:H thin films increased with increasing target power density; however, the Brewster angle decreased with the target power density. Hence, dye-sensitized solar cells using an a-C:H antireflective coating increased the CE, $V_{OC}$, and $J_{SC}$ by approximately 8.6%, 5.5%, and 4.5%, respectively.