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| 2. |
- Holmes, Natalie P., et al.
(författare)
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Engineering Two-Phase and Three-Phase Microstructures from Water-Based Dispersions of Nanoparticles for Eco-Friendly Polymer Solar Cell Applications
- 2018
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 30:18, s. 6521-6531
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Tidskriftsartikel (refereegranskat)abstract
- Nanoparticle organic photovoltaics, a subfield of organic photovoltaics (OPV), has attracted increasing interest in recent years due to the eco-friendly fabrication of solar modules afforded by colloidal ink technology. Importantly, using this approach it is now possible to engineer the microstructure of the light absorbing/charge generating layer of organic photovoltaics; decoupling film morphology from film deposition. In this study, single-component nanoparticles of poly(3-hexylthiophene) (P3HT) and phenyl-C61 butyric acid methyl ester (PC61BM) were synthesized and used to generate a two-phase microstructure with control over domain size prior to film deposition. Scanning transmission X-ray microscopy (STXM) and electron microscopy were used to characterize the thin film morphology. Uniquely, the measured microstructure was a direct input for a nanoscopic kinetic Monte Carlo (KMC) model allowing us to assess exciton transport properties that are experimentally inaccessible in these single-component particles. Photoluminescence, UV-vis spectroscopy measurements, and KMC results of the nanoparticle thin films enabled the calculation of an experimental exciton dissociation efficiency (ηED) of 37% for the two-phase microstructure. The glass transition temperature (Tg) of the materials was characterized with dynamic mechanical thermal analysis (DMTA) and thermal annealing led to an increase in ηED to 64% due to an increase in donor-acceptor interfaces in the thin film from both sintering of neighboring opposite-type particles in addition to the generation of a third mixed phase from diffusion of PC61BM into amorphous P3HT domains. As such, this study demonstrates the higher level of control over donor-acceptor film morphology enabled by customizing nanoparticulate colloidal inks, where the optimal three-phase film morphology for an OPV photoactive layer can be designed and engineered.
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| 3. |
- Quack, N., et al.
(författare)
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Silicon photonic MEMS : Exploiting mechanics at the nanoscale to enhance photonic integrated circuits
- 2019
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Ingår i: Optics InfoBase Conference Papers. - Washington, D.C. : OSA - The Optical Society.
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Konferensbidrag (refereegranskat)abstract
- With the maturing and the increasing complexity of Silicon Photonics technology, novel avenues are pursued to reduce power consumption and to provide enhanced functionality: exploiting mechanical movement in advanced Silicon Photonic Integrated Circuits provides a promising path to access a strong modulation of the effective index and to low power consumption by employing mechanically stable and thus non-volatile states. In this paper, we will discuss recent achievements in the development of MEMS enabled systems in Silicon Photonics and outline the roadmap towards reconfigurable general Photonic Integrated Circuits.
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| 4. |
- Quellmalz, Arne, et al.
(författare)
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Large-area integration of two-dimensional materials and their heterostructures by wafer bonding
- 2021
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Integrating two-dimensional (2D) materials into semiconductor manufacturing lines is essential to exploit their material properties in a wide range of application areas. However, current approaches are not compatible with high-volume manufacturing on wafer level. Here, we report a generic methodology for large-area integration of 2D materials by adhesive wafer bonding. Our approach avoids manual handling and uses equipment, processes, and materials that are readily available in large-scale semiconductor manufacturing lines. We demonstrate the transfer of CVD graphene from copper foils (100-mm diameter) and molybdenum disulfide (MoS2) from SiO2/Si chips (centimeter-sized) to silicon wafers (100-mm diameter). Furthermore, we stack graphene with CVD hexagonal boron nitride and MoS2 layers to heterostructures, and fabricate encapsulated field-effect graphene devices, with high carrier mobilities of up to 4520 cm2V-1s-1. Thus, our approach is suited for backend of the line integration of 2D materials on top of integrated circuits, with potential to accelerate progress in electronics, photonics, and sensing. The existing integration approaches for 2D materials often degrade material properties and are not compatible with industrial processing. Here, the authors devise an adhesive wafer bonding strategy to transfer and stack monolayers, suitable for back end of the line integration of 2D materials.
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| 5. |
- Quellmalz, Arne, et al.
(författare)
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Large-scale Integration of 2D Material Heterostructures by Adhesive Bonding
- 2020
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Ingår i: 2020 IEEE 33rd International Conference on Micro Electro Mechanical Systems.
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Konferensbidrag (refereegranskat)abstract
- We report the integration of graphene/hexagonal boron nitride (hBN) heterostructure devices on large-areas by adhesive wafer bonding, a method suitable for industrial mass-production. In this new approach, we stack graphene and hBN by two consecutive bond transfers whereby the graphene and its interface to hBN is not in contact with potentially contaminating polymers or adhesives at any time. To show the feasibility of our approach for back end of the line (BEOL) integration of two-dimensional (2D) material heterostructures on standard silicon substrates, we fabricated graphene/hBN devices with electrical bottom contacts using only established semiconductor manufacturing tools, processes and materials.
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| 6. |
- Wang, Xiaojing, et al.
(författare)
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Transfer printing of nanomaterials and microstructures using a wire bonder
- 2019
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Ingår i: Journal of Micromechanics and Microengineering. - : Institute of Physics Publishing (IOPP). - 0960-1317 .- 1361-6439. ; 29:12
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Tidskriftsartikel (refereegranskat)abstract
- Scalable and cost-efficient transfer of nanomaterials and microstructures from their original fabrication substrate to a new host substrate is a key challenge for realizing heterogeneously integrated functional systems, such as sensors, photonics, and electronics. Here we demonstrate a high-throughput and versatile integration method utilizing conventional wire bonding tools to transfer-print carbon nanotubes (CNTs) and silicon microstructures. Standard ball stitch wire bonding cycles were used as scalable and high-speed pick-and-place operations to realize the material transfer. Our experimental results demonstrated successful transfer printing of single-walled CNTs (100 μm-diameter patches) from their growth substrate to polydimethylsiloxane, parylene, or Au/parylene electrode substrates, and realization of field emission cathodes made of CNTs on a silicon substrate. Field emission measurements manifested excellent emission performance of the CNT electrodes. Further, we demonstrated the utility of a high-speed wire bonder for transfer printing of silicon microstructures (60 μm × 60 μm × 20 μm) from the original silicon on insulator substrate to a new host substrate. The achieved placement accuracy of the CNT patches and silicon microstructures on the target substrates were within ± 4 μm. These results show the potential of using established and extremely cost-efficient semiconductor wire bonding infrastructure for transfer printing of nanomaterials and microstructures to realize integrated microsystems and flexible electronics.
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