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The requirements for the contact metal deposited on solar cells are rising as the size of solar cells grows. Particularly, the improvement of the electric properties – especially the conductivity – is attracting interest. Light-induced plating is deemed to be a sophisticated approach to deposit a highly conductive metal layer on an arbitrarily generated seed layer. Although already in industrial operation to some extent, the mechanism is not understood in detail. In addition, the aim of avoidance of cyanide containing electrolytes for silver deposition is high. We will show voltammetric techniques are an appropriate approach investigating these topics. 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 1785-1788

Cryptographic primitives with low-latency performance have gained momentum lately due to an increased demand for real-time applications. Block ciphers such as PRINCE enable data encryption (resp. decryption) within a single clock cycle at a moderately high operating frequency when implemented in a fully-unrolled fashion. Unsurprisingly, many typical environments for unrolled ciphers require protection against physical adversaries as well. Yet, recent works suggest that most common SCA countermeasures are hard to apply to low-latency circuits. Hardware masking, for example, requires register stages to offer resistance, thus adding delay and defeating the purpose of unrolling. On another note, it has been indicated that unrolled primitives without any additional means of protection offer an intrinsic resistance to SCA attacks due to their parallelism, asynchronicity and speed of execution. In this work, we take a closer look at the physical security properties provided by unrolled cryptographic IC implementations. We are able to confirm that the nature of unrolling indeed bears the potential to decrease the susceptibility of cipher implementations significantly when reset methods are applied. With respect to certain adversarial models, e.g., ciphertext-only access, an amazingly high level of protection can be achieved. While this seems to be a great result for cryptographic hardware engineers, there is an attack vector hidden in plain sight which still threatens the security of unrolled implementations remarkably – namely the static power consumption of CMOS-based circuits. We point out that essentially all reasons which make it hard to extract meaningful information from the dynamic behavior of unrolled primitives are not an issue when exploiting the static currents for key recovery. Our evaluation is based on real-silicon measurements of an unrolled PRINCE core in a custom 40nm ASIC. The presented results serve as a neat educational case study to demonstrate the broad differences between dynamic and static power information leakage in the light of technological advancement. IACR Transactions on Cryptographic Hardware and Embedded Systems, Volume 2020, Issue 4

Technical Report (2012). doi:10.3204/XFEL.EU/TR-2012-002

To minimize shading when interconnecting single solar cells to solar modules the shingling technique can be used. Having an electrically conductive substrate this interconnection technique can be applied without any modification of the single solar cells itself. In case of electrically isolating substrates a contacting of the back metal electrode from the backside is in general not possible without modification of the substrate. Within this paper we present a possibility to interconnect flexible CIGS thin film solar cells on polyimide substrate using the shingling technique. To expose the molybdenum layer from the backside the polyimide substrate has been removed locally with a pulsed Excimer laser (248 nm wavelength, 20 ns pulse duration). To interconnect the exposed back contact with the front contact of the next solar cell the blind vias can be filled with a conductive adhesive. The surface of the exposed back contact of the CIGS solar cells has been characterized using optical microscope and SEM to acquire information on the completeness of the polymer etching and possible damages of the thin films. To characterize the exposed thin films electrically conductive-AFM images were made. First solar cells have been contacted from backside and electrically characterized. 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 3414-3417

Photovoltaic (PV) is one of the fastest growing electricity generation technologies in the world. Average annual growth rates of global PV-installations have reached around 45% for the last 15 years, which triggered a fast and ongoing reduction of production cost in PV industry. The presented work aims at consolidating historical price and cost information, deriving refined learning curves for PV modules and systems, and analysing the main factors of learning. For c-Si modules a valid learning rate of 17% is found based on a meta-analysis of various studies. In early years, even a learning rate of 30% is observed. As an example for thin-film PV, CdTe module cost reduce by 16% as the cumulated production output doubles. Interestingly, efficiency improvements contribute only in second order to the overall cost reduction for both technologies, emphasising the relevance of production excellence and economies of scale. On PV system level, a cost reduction of 14% per doubling of cumulated installed capacity is derived. Finally, a sensitivity analysis reveals that learning rate variations are only of minor influence on the overall global PV market potential. 26th European Photovoltaic Solar Energy Conference and Exhibition; 4697-4702

Hoang Lien National Park has a total area of 68569ha, located at an altitude of above sea 1000-3000m in the territory of the two provinces of Lai Chau and Lao Cai in Vietnam. It has a diversity of flora with 3252 species (including 775 endemic species and 236 endangered species), belonging to 1126 genera, 230 families and 6 different divisions. Due to the mountainous terrain, division diversity of Hoang Lien National Park’s vegetation is thus clearly characterized by high elevations. We have studied the distribution characteristics of the vegetation by high elevations in Hoang Lien National Park of Vietnam by the general survey methodology, fieldwork, remote sensing digital image processing and analysis and inheriting the preceding research results. The study results indicated the divisions in quantity, vegetation composition, especially differentiation of endemic and rare species in accordance with high elevations. Study results were preliminary used to suggest some orientations for preserving plant diversity in high elevations of the terrain. Vườn quốc gia Hoàng Liên có tổng diện tích 68569ha, nằm ở độ cao từ 1000-3000m so với mặt biển thuộc lãnh thổ hai tỉnh Lai Châu và Lào Cai của Việt Nam. Hệ thực vật của Vườn quốc gia Hoàng Liên rất phong phú với 3252 loài (trong đó có 775 loài đặc hữu và 236 loài quý hiếm), thuộc 1126 chi, 230 họ và 6 ngành khác nhau. Do địa hình núi cao, phân hóa đa dạng nên thảm thực vật của Vườn quốc gia Hoàng Liên có đặc trưng phân hóa theo đai cao rất rõ nét. Bằng các phương pháp điều tra tổng hợp, khảo sát thực địa, xử lí phân tích ảnh viễn thám và kế thừa các kết quả nghiên cứu đi trước nhóm tác giả đã tiến hành nghiên cứu đặc điểm phân bố thảm thực vật theo đai cao tại Vườn quốc gia Hoàng Liên của Việt Nam. Kết quả nghiên cứu chỉ rõ sự phân hoá về số lượng, thành phần hệ thực vật theo đai cao và phân hóa thành phần loài đặc hữu và quý hiếm theo đai cao. Bước đầu nghiên cứu đề xuất một vài định hướng bảo tồn đa dạng thực vật theo đai cao của địa hình. Journal of Vietnamese Environment, Vol 6 No 2 (2014)

A costly step in the solar cell production of crystalline silicon solar cells is the cutting of wafers. The standard technique is the multi-wire sawing with abrasive SiC slurries. The current industrial development is to reduce cost mainly by increasing the throughput, while maintaining a high surface quality. An occasionally occurring problem is the local appearance of deep groves in parts of the wafer surface. This phenomenon, generally denoted as saw marks, can affect many wafers in a batch and reduce the yield. The problem becomes more serious, when a high throughput shall be achieved. In the paper experimental results will be presented, which lead to a physical explanation of this phenomenon. They indicate that changes of the SiC particle size distribution along the sawing channel are responsible for the occurrence of saw marks. Such a change can be caused by viscosity changes due to the temperature increase and/or the accumulation of smaller particles in the slurry from particle breakage and silicon debris. A physical model was developed to describe the observed results. It is based on the motion of the particles in the slurry and their interaction with the wire and the crystal surface. Numerical solutions of the model can predict under which slurry and sawing conditions these instabilities occur. The experimental results are compared with these predictions. 28th European Photovoltaic Solar Energy Conference and Exhibition; 927-932

As grid price rises and the feed-in tariff declines, the economics of local storage become increasingly lucrative to the system owner. The attractiveness of a local storage investment is compounded in the presence of a PV grid injection cap. The larger the PV system size is relative to this cap level, the greater the opportunity exists to charge the local storage with PV production that would otherwise be dissipated without credit. This study utilizes two household demand profiles that represent the extremes of the potential for local PV self-consumption and, consequently, the range of economic potential that exists for local storage to be coupled with residential PV systems. A series of algorithms were subsequently developed to analyze the related benefit potential of delayed storage charging to target instances of excess PV production in relation to the grid injection cap. 28th European Photovoltaic Solar Energy Conference and Exhibition; 3751-3756