• Ceramist
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• v.23 no.2
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• pp.145-165
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• 2020

Halide perovskites are promising photovoltaic materials due to their excellent optoelectronic properties like high absorption coefficient, low exciton binding energy and long diffusion length, and single-junction solar cells consisting of them have shown a high certified efficiency of 25.2%. Despite of high efficiency, perovskite photovoltaics show poor stability under actual operational condition, which is the mostly critical obstacle for commercialization. Given that the stability of the perovskite devices is significantly affected by charge-transporting layers, the use of inorganic charge-transporting layers with better intrinsic stability than the organic counterparts must be beneficial to the enhanced device reliability. In this review article, we summarized a number of studies on the inorganic charge-transporting layers of the perovskite solar cells, especially focusing on their effects on the enhanced device reliability.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.95-98
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• 2003

Tin doped indium oxide(ITO) films, which is widely used as a transparent conductor in optoelectronic devices such as solar cell, liquid crystal display, plasma display panel, thermal heater, and other sensors, were prepared by using the capacitively coupled DC magnetron sputtering method. The influence of the substrate temperature, working gas pressure and deposition time on the electrical, optical and morphological properties were investigated experimentally. ITO films with the optimum growth conditions showed resistivity of $2.36{\times}10^{-4}(\Omega}-cm$ and transmittance of 86.28% for a film 680nm thick in the wavelength range of the visible spectrum.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1430-1432
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• 2003

Al doped Zinc Oxide(ZnO:Al) films, which is widely used as a transparent conductor in optoelectronic devices such as solar cell, plasma display panel, thermal heater, and other sensors, were prepared by using the capacitively coupled DC magnetron sputtering method. The influence of the substrate temperature, working gas pressure and deposition time on the electrical, optical and morphological properties were investigated experimentally. ZnO:Al films with the optimum growth conditions of working gas pressure and substrate temperature showed resistivity of $9.64{\times}10^{-4}\;{\Omega}$-cm and transmittance of 90.02% for a film 860nm thick in the wavelength range of the visible spectrum.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.11
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• pp.954-958
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• 2000

The characterization of zinc diffusion processes applied for high-speed avalanche photodiodes has been examined. The different diffusion process conditions for InP test structures were explored. The zinc diffusion profiles, such as the diffusion depth and the zinc dopant concentration, were examined using secondary ion mass spectrometry with varying the process variables and material parameters. It is observed that the diffusion profiles are severly impacted on the process parameters, such as the amount of Zn$_3$P$_2$ source and the diffusion time, as well as material parameters, such as doping concentration of diffusion layer. These results can be utilized for the high-speed avalanche photodiode fabrication.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.296-299
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• 2008

최근 통신시스템과 핸드폰, PDA등의 통신기기들의 발전에 따라 사용자들은 높은 데이터 전송률과 고속의 통신서비스를 요구하고 있다. 이러한 상황에서 유 무선 통합 시스템인 Radio-over-Fiber(RoF) 시스템은 그 대안으로 대두되고 있다. 본 논문에서는 광전자소자를 선 왜곡 방식에 적용하여 광 송신기의 선형성을 향상시키는 방법을 제안하였다. 선 왜곡 방식은 두 개의 루프로 구성되어 있으며, 광 부품인 레이저 다이오드와 포토 다이오드 그리고 RF 부품인 위상변위기, 감쇄기, RF 결합/분배기, RF 증폭기를 사용하였다. 메인 루프에서 주 레이저 다이오드의 비선형성에 의해 발생된 왜곡신호성분은 보조 루프에서 부 레이저 다이오드를 이용하여 추출된 선 왜곡신호에 의해서 제거된다. 제안된 선형화 기법을 적용하여 2.4 GHz에서 선형화 기법을 적용하기 전보다 3차 상호변조 왜곡성분이 약 30dB 향상된 결과를 얻었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.106-107
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• 2007

We fabricated anodic aluminium oxides (AAO) on Si and sapphire substrates from the electrochemical reactions of thin AI films in an aqueous solution of oxalic acid. The thin AI films have deposited on Si and Sapphire substructure by using E-beam evaporation and thermal evaporation, respectively. The formation of AAO structures has investigated from FE-SEM measurement image and showed randomly distributed phase of nanoholes instead of the periodic lattice of photonic crystals. The AAO structure on sapphire shows the double layers of nanoholes.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1323-1324
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• 2007

전기방사법을 이용하여 PVK-CdTe 용액으로 하이브리드 나노파이버를 제조하였다. 하이브리드 나노파이버 형상은 광학현미경과 Scanning Electron Microscope으로 관찰되었으며, 직경은 $300nm\;{\sim}\;30{\mu}m$이고, 길이는 $500\;{\mu}m$이상 이였다. PVK-CdTe 하이브리드 나노파이버의 Photoluminescence 측정을 통하여 하이브리드 나노파이버내에 나노입자특성을 유지한 CdTe 나노입자의 존재를 확인하였으며, 대기와 진공 중에서의 I-V 측정을 통해 진공 상태에서보다 대기상태에서 약 2배 정도 전류가 증가한다는 것을 알았다.

• Transactions on Electrical and Electronic Materials
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• v.13 no.1
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• pp.6-9
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• 2012

In this study, we carried out an investigation of the etching characteristics (etch rate, selectivity to $SiO_2$) of ZnO thin films in $N_2/Cl_2$/Ar inductivity coupled plasma. A maximum etch rate and selectivity of 108.8 nm/min and, 3.21, respectively, was obtained for ZnO thin film at a $N_2/Cl_2$/Ar gas mixing ratio of 15:16:4 sccm. The plasmas were characterized by optical emission spectroscopy. The x-ray photoelectron spectroscopy analysis showed the efficient destruction of oxide bonds by ion bombardment. An accumulation of low volatile reaction products on the etched surface was also shown. Based on this data, an ion-assisted chemical reaction is proposed as the main etch mechanism for plasmas containing $Cl_2$.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.149.1-149.1
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• 2013

Noble metal silicides are widely used in silicon based microelectronic and optoelectronic devices. Among them, as compared to other silicides, structural and electronic properties of platinum silicide (PtSi) are found to be less sensitive to change in its dimensions. PtSi is known to overcome the junction spiking problems of Al-Si contacts. Present study is regarding the spatial evolution of platinum silicide in Pt/SiOx/Si. Scanning photoelectron emission microscopy (SPEM) was used for this purpose. SPEM images were obtained for pristine samples and after an annealing at $500^{\circ}C$ for 1 hr. Core-level spectra were recorded at different points in SPEM images contrasted by the intensity of Pt 4f7/2. Both Pt 4f and Si 2p spectra reveal the formation of PtSi after annealing. However, in contrast to earlier reports, PtSi formation is found to be non-uniform confirmed by the SPEM images and from the core level spectra taken at different intensity points.

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.08a
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• pp.69.4-69
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• 1998