Report
Teaser, summary, work performed and final results
Periodic Reporting for period 1 - INDEED (Innovative Nanowire DEvicE Design)
Teaser
The main objective of the INDEED ITN is to develop the next-generation electronic and optical devices based on semiconductor nanowires (NWs) by studying the underpinning technology that can pave the way to future industrial applications. NWs are nanoscale materials produced in...
Summary
The main objective of the INDEED ITN is to develop the next-generation electronic and optical devices based on semiconductor nanowires (NWs) by studying the underpinning technology that can pave the way to future industrial applications. NWs are nanoscale materials produced in laboratories and exhibit unique properties that make them ideal building blocks to develop next-generation electronic devices, e.g. intelligent sensors, solar cells, transistors, quantum light sources and lasers, quantum computers, etc. Developing these devices requires precise control of the NW growth by gaining an insight of the underpinning theory and processing models, developing novel characterisation techniques, scalable processes and new device concepts that overcome current limitations. To achieve this, INDEED brings together leading scientific experts from 12 top academic institutions in Europe and 13 industry partners with an excellent track record of converting cutting-edge scientific ideas into market products, to train 15 future research leaders (ESRs). Similar to Silicon technology led to significant societal changes (modern computers, digital economy and social media) NWs are seen as key enablers to overcome current limitations and to develop future devices, which could facilitate big data processing & artificial intelligence and unforeseen applications. Fig.1 depicts a technology developed by INDEED to produce NW-based superconducting junctions, the building blocks for future quantum computers able to perform thousands of times better than their current counterparts. Our main objectives are: (i) Training: Deliver the best scientific research and transferable skills to the ESRs so that they publish high impact journal papers and communicate our discoveries to the public (Fig.2); (ii) Underpinning technology: Understand and control the NWs properties for scalable device fabrication and monolithic integration; (iii) Emerging device concepts: Develop new device concepts based on NWs for future and emerging technologies; (iv) Scaling up and technology demonstrators: Develop NW-based technology demonstrators to address volume processing; (v) Innovative design approaches: Develop cross-cutting design methodologies for the optimisation of nanoscale device fabrication concepts.
Work performed
Summary of achievements:
•Underpinning technology: New NW growth processes were developed to control NW structural, electronic and optical properties. To control NWs functional properties, experimental studies of epitaxial growth were conducted and coupled with new growth theory and models because their understanding is essential to fine-tune NWs properties such that they perform the ultimate device functions. Growth recipes for suppressing unwanted effects and sharpening NW junction structures were formulated to facilitate the interaction between matter and light.
•Emerging device concepts: Theoretical studies of size distribution of ensembles of Ga-catalysed GaAs NW nanostructures led us to develop techniques that improve size NW homogeneity. Unlike traditional electronic devices, we have demonstrated that embedding GaAs NWs in a polymer membrane produces a device that can perform multiple functions simultaneously, e.g. pressure sensors and non-volatile memory. We also developed fabrication processes to produce and organise kinked NWs that form NW superconducting junctions. These are the fundamental building blocks for quantum computers. Finally, a semi-automated robotic hardware capable of manipulating nanoscale NW devices was developed to address systematic post-fabrication testing of NW structures.
•Scaling up and technology demonstrators: We found that NW size uniformity in self-assisted GaAs NWs grown on silicon by MBE can be drastically improved by increasing supersaturation. This constitutes a milestone for combining ordered NW arrays and related devices on a chip in reproducible and controllably. A process combining various deposition techniques was developed to control ZnO NW growth direction, size, morphology, orientation and crystal phase purity on large area substrates. Likewise, DNA-based biopolymers offer an excellent platform for NW batch production where using nucleobase coordination polymers can help introduce electrical conduction in DNA.
•Innovative design approaches: The first studies consisting of applying Inventive Problem Solving (TRIZ)to Nanotechnology show a great potential; i.e. TRIZ can be very effective for developing new concepts in nanotechnology if adapted for nanotechnologists. A method has been developed to help researchers simplify conceptual design and conduct fast search in thousands of scientific articles and patents.
•ESR Training is conducted at the host university for the day-to-day local training while INEED provides network training to all ESRs, covering knowledge and intellectual abilities, research skills, Personal effectiveness and communication (e.g. presentation and writing, planning, reports, networking, social media, outreach and dissemination). In addition to local training, we conducted 7 major network training events, e.g. conferences, workshops, academic and industrial secondments.
•Dissemination & Communication: A publicly accessible website (www.indeednetwork.com) provides information on publications, conferences, events and outreach. INDEED ESRs are very active in social media via YouTube, Facebook, WhatsApp and LinkedIn. The ESRs’ research led to 15 journal papers, 31 conferences papers and 2 poster competition prizes including a Best Poster prize at MRS ( Boston, USA 2018). Our ESRs contributed to 3 major outreach events to communicate our research to the general public: Celebrate Science Festival- Durham, UK; Notte di ricercatore- Rome, Italy and Night of Culture- Lund, Sweden attracted more than 5000 visitors each.
Final results
New NW growth processes have been developed to control the structural, electronic and optical properties. For next generation solar cells, ordered arrays of NWs are required with high yield and uniformity. For example, we have reported the gold-free templated growth of III–V nanowires by molecular beam epitaxy using an approach that enables patternable and highly regular branched nanowire arrays on a far greater scale than what has been reported thus far. We have shown that the uniformity can be enhanced by increasing the As4 flux during growth. We have gained control of the optical properties - showing that tuning light emission in bulk and quantum structures by strain constitutes a complementary method to engineer functional properties of semiconductors. For the emerging field of quantum computing, we have developed kinked NW-based superconducting junctions, a fundamental step towards the design of quantum computers. Our ESRs have published 15 journal articles which detail the state-of-the-art in NW research, paving the way for many more breakthroughs in the project, some with hitherto unforeseen applications. Through INDEED, a pan-European network of academic and industrial groups is operating at the cutting edge of research and development. We have established a distributed, multicultural laboratory, with ESRs regularly moving between partner organisations to carry out their research. The ESRs are also engaging with the general public across Europe through outreach to promote the research carried out within INDEED.
Website & more info
More info: https://www.indeednetwork.com.