http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Hyeongsik Park,Doyoung Kim,Eun-Chel Cho,Shahzada Qamar Hussain,Jeongeun Park,Donggun Lim,Sangho Kim,Subhajit Dutta,Mallem Kumar,Youngkuk Kim,Junsin Yi 한국물리학회 2020 Current Applied Physics Vol.20 No.1
In this study, we investigated the effect of plasma treatment on an indium tin oxide (ITO) film under an ambient Ar atmosphere. The sheet resistance of the plasma-treated ITO film at 250W (37.6 Ω/sq) was higher than that of the as-deposited ITO film (34 Ω/sq). Plasma treatment was found to decrease the ITO grain size to 21.81 nm, in comparison with the as-deposited ITO (25.49 nm), which resulted in a decrease in the Hall mobility. The work function of the Ar-plasma-treated ITO (WFITO=4.17 eV) was lower than that of the as-deposited ITO film (WFITO=5.13 eV). This lower work function was attributed to vacancies that formed in the indium and oxygen vacancies in the bonding structure. Rear-emitter silicon heterojunction (SHJ) solar cells fabricated using the plasma-treated ITO film exhibited an open circuit voltage (VOC) of 734 mV, compared to SHJ cells fabricated using the as-deposited ITO film, which showed a VOC of 704 mV. The increase in VOC could be explained by the decrease in the work function, which is related to the reduction in the barrier height between the ITO and a-Si:H (n) of the rear-emitter SHJ solar cells. Furthermore, the performance of the plasma-treated ITO film was verified, with the front surface field layers, using an AFORS-HET simulation. The current density (JSC) and VOC increased to 39.44 mA/cm2 and 736.8 mV, respectively, while maintaining a WFITO of 3.8 eV. Meanwhile, the efficiency was 22.9% at VOC=721.5 mV and JSC=38.55 mA/cm2 for WFITO=4.4 eV. However, an overall enhancement of 23.75% in the cell efficiency was achieved owing to the low work function value of the ITO film. Ar plasma treatment can be used in transparent conducting oxide applications to improve cell efficiency by controlling the barrier height.
Present Status of Thin Film Solar Cells Using Textured Surfaces: A Brief Review
Hyeongsik Park,SHAIKHMOHAMMAD IFTIQUAR,Anh Huy Tuan Le,Shihyun Ahn,강준영,Yongjun Kim,Junsin Yi,Sunbo Kim,신명훈 한국전기전자재료학회 2016 Transactions on Electrical and Electronic Material Vol.17 No.5
This is a brief review on light trapping in Si based thin film solar cells with textured surfaces and transparentconducting oxide front electrodes. The light trapping scheme appears to be essential in improving device efficiencyover 10%. As light absorption in a thin film solar cells is not sufficient, light trapping becomes necessary to beeffectively implemented with a textured surface. Surface texturing helps in the light trapping, and thereby raises shortcircuit current density and its efficiency. Such a scheme can be adapted to single junction as well as tandem solar cell,amorphous or micro-crystalline devices. A tandem cell is expected to have superior performance in comparison to asingle junction cell and random surface textures appears to be preferable to a periodic structures.
Hyeongsik Park,Jae Hyun Cho,Jun Hee Jung,Pham Phong Duy,Anh Huy Tuan Le,Junsin Yi 한국태양광발전학회 2017 Current Photovoltaic Research Vol.5 No.3
High efficiency thin film solar cells require an absorber layer with high absorption and low defect, a transparent conductive oxide (TCO) film with high transmittance of over 80% and a high conductivity. Furthermore, light can be captured through the glass substrate and sent to the light absorbing layer to improve the efficiency. In this paper, morphology formation on the surface of glass substrate was investigated by using HF, mainly classified as random etching and periodic etching. We discussed about the etch mechanism, etch rate and hard mask materials, and periodic light trapping structure.
Hyeongsik Park,이윤정,박진주,김영국,이준신,이영석,김상호,박창균,임경진 한국전기전자재료학회 2018 Transactions on Electrical and Electronic Material Vol.19 No.3
In this paper, we report a technical approach regarding an amorphous silicon (a-Si)/crystalline silicon (c-Si) heterojunctionsolar cell to solve the previous issues, and we investigate the applications of front and back transparent conductive oxides(TCOs) on this high-effi ciency solar cell. The presentation of front and rear-emitter structure solar cells is included, andwe investigate the TCO-material candidates for the Si heterojunction (SHJ) solar cell according to the electrical and opticalproperties. A high-quality TCO fi lm is very important because it is linked to the effi ciency of the c-Si-based silicon solarcell. The intention here is the applying of a high-effi ciency SHJ solar cell by fabricating the high-quality TCO materials ofthe investigation of this study.
Moisture evaporation prediction model for fresh storage of vegetables in refrigerator
Hyeongsik Kim,Jooshin Kim,Youngmin Park,박상후 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.4
This work aims to predict the moisture evaporation in vegetable storage drawers of a household refrigerator with considering the operating conditions of a refrigerator and to propose a prediction model of moisture preservation for a long-term storage of vegetables. An experimental equipment was setup to evaluate the operating conditions, such as temperature and humidity control, cold airflow path, and structural design of a drawer. Moisture evaporation in fresh vegetables was evaluated quantitatively, and a new predictive model of moisture evaporation was developed on the basis of the data. The coefficient of determination was 93.2 % in the prediction model developed when spinach and bok choy were used in the basic experiment, which matched well with the experimental data obtained from a real refrigerator test with difference of approximately 0.4 %. We believe that the proposed approach can be utilized in the initial design stage of a vegetable drawer of a household refrigerator and is expected to be implemented in diverse applications related to fresh storage of vegetables.
Park, Hyeongsik,Shin, Myunghun,Kim, Hyeongseok,Kim, Sunbo,Le, Anh Huy Tuan,Kang, Junyoung,Kim, Yongjun,Pham, Duy Phong,Jung, Junhee,Yi, Junsin Elsevier 2017 Optical materials Vol.66 No.-
<P><B>Abstract</B></P> <P>A comparative study of 3-dimensional textured glass morphologies with variable haze value and chemical texturing of the glass substrates was conducted to enhance light trapping in silicon (Si) thin film solar cells (TFSCs). The light trapping characteristics of periodic honeycomb structures show enhanced transmittance and haze ratio in numerical and experimental approaches. The periodic honeycomb structure of notched textures is better than a random or periodic carved structure. It has high transmittance of ∼95%, and haze ratio of ∼52.8%, and the haze property of the angular distribution function of transmittance shows wide scattering angles in the long wavelength region because of the wide spacing and aspect ratio of the texture. The numerical and experimental approaches of the 3-D texture structures in this work will be useful in developing high-performance Si TFSCs with light trapping.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 3-D Light trapping structures are investigated for Si thin film solar cells. </LI> <LI> A glass texturing method is developed using chemical solutions of diluted HF. </LI> <LI> FDTD simulation shows a notched periodic honeycomb texture will be effective one. </LI> <LI> Periodic texturing shows better light scattering performance than random structures. </LI> <LI> Fabricated periodic honeycomb structure shows high transmittance and haze values. </LI> </UL> </P>