| 1. |
- Chebaeva, Natalia, et al.
(författare)
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Dealing with the eco-design paradox in research and development projects : The concept of sustainability assessment levels
- 2021
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 281
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Tidskriftsartikel (refereegranskat)abstract
- Although plenty of research has been carried out to develop a multitude of sustainability assessment methods, few guidelines and criteria have been established to help practitioners and researchers find the most appropriate method for a specific case. Studies have shown the importance of integrating sustainability assessments when conducting research and development activities, but have not provided direct links to available sustainability assessment methods. To address the so-called "eco-design paradox", this paper describes a systematic classification system for the available sustainability assessment methods. To support the early integration of sustainability assessments in research and development, we inductively derived the concept of sustainability assessment levels from the well-known concept of technology readiness level. In total, 33 sustainability assessment methods were considered. We performed an expert-based correspondence analysis based on the availability of information to perform these methods and the demand for specific information at respective technology readiness level. Thereafter, a cluster analysis was performed, creating four distinct clusters which were finally interpreted as sustainability assessment levels. The provided concept supports interdisciplinary research projects in that it provides an overview of and guideline for possible sustainability assessment methods that match the respective technology readiness level. This enables researchers to integrate sustainability assessment into respective research and development projects and further modify and develop the theoretically synthetized concept based on empirical case studies.
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| 2. |
- Junige, Marcel, et al.
(författare)
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Atomic Layer Deposition of Al2O3 on NF3-pre-treated graphene
- 2015
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Ingår i: NANOTECHNOLOGY VII. - : Society of Photo-optical Instrumentation Engineers (SPIE). - 9781628416428
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Konferensbidrag (refereegranskat)abstract
- Graphene has been considered for a variety of applications including novel nanoelectronic device concepts. However, the deposition of ultra-thin high-k dielectrics on top of graphene has still been challenging due to graphenes lack of dangling bonds. The formation of large islands and leaky films has been observed resulting from a much delayed growth initiation. In order to address this issue, we tested a pre-treatment with NF3 instead of XeF2 on CVD graphene as well as epitaxial graphene monolayers prior to the Atomic Layer Deposition (ALD) of Al2O3. All experiments were conducted in vacuo; i. e. the pristine graphene samples were exposed to NF3 in the same reactor immediately before applying 30 (TMA-H2O) ALD cycles and the samples were transferred between the ALD reactor and a surface analysis unit under high vacuum conditions. The ALD growth initiation was observed by in-situ real-time Spectroscopic Ellipsometry (irtSE) with a sampling rate above 1Hz. The total amount of Al2O3 material deposited by the applied 30 ALD cycles was cross-checked by in-vacuo X-ray Photoelectron Spectroscopy (XPS). The Al2O3 morphology was determined by Atomic Force Microscopy (AFM). The presence of graphene and its defect status was examined by in-vacuo XPS and RAMAN Spectroscopy before and after the coating procedure, respectively.
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| 3. |
- Lupina, Grzegorz, et al.
(författare)
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Residual Metallic Contamination of Transferred Chemical Vapor Deposited Graphene
- 2015
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 9:5, s. 4776-4785
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Tidskriftsartikel (refereegranskat)abstract
- Integration of graphene with Si microelectronics is very appealing by offering a potentially broad range of new functionalities. New materials to be integrated with the Si platform must conform to stringent purity standards. Here, we investigate graphene layers grown on copper foils by chemical vapor deposition and transferred to silicon wafers by wet etching and electrochemical delamination methods with respect to residual submonolayer metallic contaminations. Regardless of the transfer method and associated cleaning scheme, time-of-flight secondary ion mass spectrometry and total reflection X-ray fluorescence measurements indicate that the graphene sheets are contaminated with residual metals (copper, iron) with a concentration exceeding 10(13) atoms/cm(2). These metal impurities appear to be partially mobile upon thermal treatment, as shown by depth profiling and reduction of the minority charge carrier diffusion length in the silicon substrate. As residual metallic impurities can significantly alter electronic and electrochemical properties of graphene and can severely impede the process of integration with silicon microelectronics, these results reveal that further progress in synthesis, handling, and cleaning of graphene is required to advance electronic and optoelectronic applications.
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