http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Thin wafer를 이용한 결정질 실리콘 태양전지의 효율개선 방안
손혁주(Son, Hyukjoo),박용환(Park, Yonghwan),김덕열(Kim, Deokyeol) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.11
결정질 실리콘 태양전지의 원가에서 Wafer는 60~70%의 매우 높은 비중을 차지하고 있다. 많은 연구들이 원가 절감을 위하여 Wafer의 두께를 감소시키는 것에 집중하고 있다. 그러나 Wafer 두께의 감소는 태양전지의 효율 감소와 공정 진행 중에 파손율이 상승하는 등의 문제가 발생한다. 이에 본 논문에서는 결정질 태양전지 구조 중에서 24.7% 이상의 최고 변환 효율을 갖는 PERL(Passivated Emitter, Rear Locally diffuse) 구조를 대상으로 wafer 두께 감소에 따른 변환 효율 감소의 원인과 해결 방안을 제시하고자 한다. Simulation으로 확인한 결과 370 um 두께의 wafer에서 24.2 %의 효율은 50 um 두께의 wafer에서는 20.8 %로 감소함을 확인할 수 있었다. 얇아진 wafer에서 감소한 효율을 개선하기 위하여 후면 recombination velocity, 후면 fixed charge density, 후면 산화막 두께 등을 다양화하여, 각각의 경우에 대한 cell의 효율 변화를 살펴보았다. 그 결과 후면 recombination velocity, 후면 fixed charge density, 후면 산화막 두께를 최적화 하여, 각각 2.8 %p, 1.5 %p, 2.8 %p의 효율 개선 효과를 얻었다. 위 세 가지 효과를 동시에 적용하면 50 um wafer에서 370 um wafer 효율의 결과와 근접한 24.2 %의 효율을 얻을 수 있었다. 향후에는 위의 결과를 바탕으로 실제 실험을 통하여 확인할 계획이다.
Thermal oxidation을 이용한 결정질 실리콘 태양전지의 selective emitter 형성 방법에 대한 simulation
최용현(Choe, Yonghyon),손혁주(Son, Hyukjoo),이인지(Lee, Inji),박재근(Park, Jeagun),박용환(Park, Yonghwan) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.11
결정질 실리콘 태양전지의 효율을 향상시키기 위하여 수광면에 서로 다른 도핑농도를 가지는 고농도 도핑영역과 저농도 도핑영역으로 이루어진 emitter를 형성하는 것이 요구되며 이를 selective emitter라 칭한다. Selective emitter를 형성하면 고농도 도핑영역에서 금속전극과 저항 접촉이 잘 형성되기 때문에 직렬 저항이 최소화되고 저농도 도핑영역에서는 전하 재결합의 감소로 인하여 태양전지의 변환효율이 상승하는 이점이 있다. Selective emitter의 형성방법은 이미 다양한 방법이 제안되고 있으나, 본 연구에서는 기존에 제시된 방법과는 다르게 열산화 시 dopant redistribution에 의한 Boron depletion 현상을 이용하여 selective emitter를 형성하는 방법을 제안하였고, 이를 Simulation을 통하여 검증하였다. 초기 emitter 확산 후 junction depth는 0.478um, 면저항은 104.2{Omega}/sq. 이었으며, nitride masking layer 두께는 0.3um로 설정하였다. 1100?C에서 30분간 습식산화 공정을 거친 후 nitride mask가 있는 부분의 junction depth는 1.48um, 면저항은 89.1{Omega}/sq의 값을 보였고, 산화막이 형성된 부분의 junction depth는 1.16um, 면저항은 261.8{Omega}/sq의 값을 보였다. 위 조건의 구조를 가진 태양전지의 변환 효율은 19.28%의 값을 나타내었고 Voc, Jsc 및 fill factor는 각각 645.08mV, 36.26mA/cm², 82.42%의 값을 보였다. 한편 일반적인 구조로 설정한 태양전지의 변환 효율, Voc, Isc 및 fill factor는 각각 18.73%, 644.86mV, 36.26mA/cm², 80.09%의 값을 보였다.
Kwangsoo Lee,이준신,손혁주,Hyungjun Park,김재홍,Jeoungin Lee,김경해,Kyungsoo Jang,정성욱 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.6
Thin films of high dielectric constant materials, specifically titanium dioxide, were investigated as potential replacements for silicon dioxide, which is generally used as a blocking layer for nonvolatile memory devices. A silicon-oxynitride layer using nitrous-oxide plasma as a tunneling layer and using titanium-dioxide as a blocking layer was deposited to fabricate nonvolatile memory on rough poly-silicon. Titanium dioxide thin films were deposited using atmospheric pressure chemical vapor deposition and spectroscopic ellipsometry and scanning electron microscopy were used to measure the physical properties. A metal-insulator-semiconductor device was fabricated to measure the current density-electric field and a nonvolatile memory device on glass was fabricated to measure the gate voltage - drain current, drain voltage - drain current and retention characteristics. The leakage current density of the sample deposited at 250℃ was the lowest (1.4 x 10-9A/mm² at 2 MV/cm). The threshold voltage shift of the nonvolatile memory device on glass was 1.6 V and the subthreshold swing (~270 mV/decade based on the maximum slope in the transfer curve) and the on/off current ratio (~10 6) remained nearly constant during the programming/erasing operations.
Graph Attention을 적용한 라이다 물체 인식 시스템
남택규(Taekkyu Nam),손혁주(Hyukju Sohn),허건수(Kunsoo Huh) 한국자동차공학회 2021 한국자동차공학회 부문종합 학술대회 Vol.2021 No.6
In order to perform fully autonomous driving, it is essential to recognize surrounding objects. With the recent development of deep learning, various studies are being conducted to classify objects around vehicles. In object recognition based on deep learning, there are a point cloud-based model1 and an image-based model2. The image-based model has a sensitive limitation to the light and weather of the camera sensor. On the other hand, since the LiDAR sensor is relatively less affected by light and weather, the reliability of the point cloud-based model is higher. However, the data in the point cloud has a non-uniform distribution. This causes information loss in the convolution process and uses a method of processing a point cloud as a graph to effectively process it. In this paper, after making a graph using a point cloud as a node, we apply a Graph Attention Network (GAT) that uses an attention mechanism to learn by assigning weights to important nodes to encode the characteristics of each node. This information is used to classify the object and predict the bounding box through two Multi-Layer Perceptrons (MLPs). As a result, the loss of node characteristic information is prevented by giving weight to the information of the target node and the neighboring nodes that are highly relevant.
이준신,조재현,박형준,김현민,손혁주,김재홍,허종규,손선영,박근희,남은경,정동근 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.6
In organic light-emiting diodes (OLEDs), both the electrons and the holes ned to be injected efficiently to obtain the best device performance. This means that a smal injection barier height at the indium-tin oxide (ITO)/organic interface is required. The insertion of an insulating layer betwen the ITO and the organic layers leads to a significant improvement in the charge injection and the electroluminescence output. In this study, the surface of the ITO anode in OLEDs was treated with an HfOX deposition proces by using an atomic-layer chemical- vapor deposition system (ALCVD). The OLEDs fabricated on the HfOX-treated ITO anode showed a lower impedance and a higher conductance and capacitance. The changes in the capacitance, the conductance and the impedance were atributed to the enhanced carier tunneling and to a change in the work function of ITO. In this work, we used an impedance spectroscopy analysis to determine the effect of the HfOX treatment on the surface of ITO and to model the equivalent circuit for OLEDs. Impedance spectroscopy is one of the most powerful tools used to study equivalent circuit models for and the charge carier dynamics and the dielectric properties of organic devices. Devices with an ITO/organic material/Al structure could be modeled as resistances and capacitances aranged in paralel or in series. The number of elements depend on the composition of the structure, esentialy the number of layers and the contacts.
자율주행차 개발 및 평가를 위한 테스트 시나리오 생성 프레임워크
성지훈(Jihoon Sung),김기훈(Gihoon Kim),김웅진(Eungjin Kim),손혁주(Hyukju Shon),양찬욱(Chanuk Yang),최재호(Jaeho Choi),허건수(Kunsoo Huh) 한국자동차공학회 2022 한국자동차공학회 학술대회 및 전시회 Vol.2022 No.11
In general, vehicle development process follows V-Process, which consists of multiple development and evaluation stages, so test scenarios can be one of the ways to set the direction of development. In the case of Advanced Driver Assistance System(ADAS), the evaluation of their performance is conducted in functional unit level, such as lane change assist and lane keeping. However, as the level of the autonomous driving increases, it is necessary to evaluate autonomous driving technology not only at the functional units level, but also whether it is possible to drive within Operational Design Domain(ODD). Until now, for systems higher than level 2, the testing has been replaced by achieving the target distance in the corresponding ODD, but since most of distances are filled on general driving conditions, safety cannot be guaranteed against to various events that may occur in there. Therefore, recently, many studies have been studied to evaluate various situations at the scenario level, such as the PEGASUS project. In this paper, we analyze the already published scenario-level approaches, and construct the relationship between them. Then, an integrated test scenario generation framework is proposed based on organized contents. The proposed method can derive test scenarios for high-level autonomous driving as well as low-level one, and is expected to be used to generate test scenarios for future technology development.