Smart Flexible Quantum Dot Lighting

Lead Research Organisation: University of Cambridge
Department Name: Engineering

Abstract

cQD are attracting significant interest as the key components for next-generation smart displays/lightings, photo detectors and image sensors, and solar cells. This is because they show excellent and unique physical properties such as i) high sensitivity and quantum efficiency, ii) excellent colour gamut with narrow emission (absorption) bandwidths, iii) colour tunability/band gap engineering through size control, iv) high photostability and v) high air stability as they are based on inorganic materials. Therefore, since the latest results on cQD LEDs and image sensors/photodetector have demonstrated the possibility of integration of cQD optoelectronics with current semiconducting technologies, the pace of research in the cQD area has been accelerated dramatically and an increasing number of research groups and companies are currently active in this area worldwide.
The investigators expect that cQD LED will replace current technologies through: (1) Superior reliability of the inorganic structure in an almost air barrier free architecture w.r.t OLED (WVTR of 10-6 g/m2/day), (2) Lower power consumption and low product cost, 60 and 50 % less than current OLED, respectively, and (3) Colour purity of 110% or greater compared to typically 80% for OLED.
This project will address will enhance the current state of the art to achieve cost reduction through using continuous, as opposed batch, cQD synthesis, mono layer resin free processing, all inorganic interface materials such as ETL (electron transport layer) and HTL (hole transport layer), device integration and packaging for EL cQD LED, with Cd-free cQDs for smart lighting and displays.
The project proposed builds upon research established in the investigators' groups in Cambridge and Oxford. We are well equipped with facilities for pilot fabrication using technologies which will underpin the commercialisation of cQD LED based lighting/displays. The final deliverable will be energy efficient 4" active devices with predictable life times, and sustainable high brightness for flexible smart lighting. The elements of the smart light which will include colour hue and brightness control based on active matrix switching of pixels will also be applicable to displays, but without the same high pixel definition.
We shall explore the design and synthesis of Cd-free cQDs with the core/shell structures using continuous flow production methods which can then be incorporated into active devices. Key to successfully implementing devices are the scalable production of high quality cQDs with specific surface passivation and functionalisation which limit the effects of impurities and defects and produce high quality thin films with well understood interfaces. In this project we will use scalable production techniques that can be transferred to in-line process for mass production. We shall focus on the manufacturing and processing aspects to create mono layer-controlled cQD films with entire close-packed and almost void free structure using dry-transfer printing methods. This will enhance efficiency and reliability of film for the desired mode of devices. Interface control based on a monolayer level layer-by-layer transfer process will be employed in order to obtain highly uniform monolayers which can be expanded to multilayer stacked film processing including interface layers. The interface materials for emissive cQD film with inorganic HTL and ETL layer for EL devices will also be designed and fabricated at the device integration step (WP 2-3). Driving electronics using TFTs will be designed for reliable and stable operation.
Industrial partners in the supply chain for smart flexible lighting production, are: CDT Ltd for materials, lighting, metrology; CPI Ltd, Dupont-Teijin Films UK for flexible films for lighting; Emberion UK, Dyson, FlexEnable, Samsung UK for device processing, and system integration; Aixtron UK for TCF; Nanoco and Merck as materials suppliers and EAB members.

Planned Impact

Science and technological innovation on colloidal Quantum Dots (cQD) has the potential to increase energy efficiency in visual and lighting systems while also enabling new paradigms of functionality. This project will advance cQD-based scalable materials, their manufacturing processes and device fabrication tools, which can be used holistically to enhance the manufacturability, reliability and as a result cost of devices. We are supported by a consortium of UK industrial partners, which have the capability to translate the research into commercial impact. Therefore, in terms of impact, our primary aim is to maximise opportunities for the UK to develop and grow its scientific and industrial leadership and deploy transformative manufacturing platform technologies into a new generation of smart flexible cQD displays and lighting systems. The UK electronic industry employs more than 800,000 people and contributes to more than 5% of GDP. Also UK photonics counts 1500 companies employing another 70,000 people with £10.5bn output and 8% CAGR. Crucially, the scope of this project encompasses the broader integration challenges of electronics, photonics, materials and manufacturing process. Recent market analysis forecast that cQDs will enable a market for devices and components worth over $11bn by 2026. The demand for cQDs will grow from less than 100 kg today to several tons over the next decade. The UK plays a key role in advancing the fundamental research fields of materials and device manufacturing process and tools and is a key contributor to the supply chain with cQD materials, Know-how and IP. Specifically, the UK leads in the field of cQD materials and related IP generation serving the global markets of lighting, displays, solar cell, optical sensors, and healthcare, based on cQD technologies, with access to a SAM in excess of $8.65bn worldwide by 2022. The Universities of Cambridge and Oxford, in partnership, will play a pivotal role driving innovation through the merging field of smart flexible lighting and possible expansion to displays.
Although competition is fierce, the global marketplace is huge with much space for regional and application based customisation within the context of smart lighting. The emerging smart lighting market presents an opportunity worth at least £1bn/pa globally since 2020. This is especially relevant for SMEs and start-ups which can use the technology for lighting design within the creative industries. A whole new market around creative lighting is poised to emerge once QD based smart lighting becomes available. The UK, with its lead role in the creative and service industries, is well placed to become a global leader in these new markets based around smart lighting. To support relationships with industry we will engage with Cambridge Knowledge Transfer Facilitators, as well as with both Cambridge Enterprise and Isis Innovation. Activities might include regional research symposia and the development of a series of 'Industry Briefing' notes disseminated both as press releases and directly to the companies identified through market research. We will work closely with our UK industrial partners; both those we have currently identified and those we intend to recruit as the project unfolds, and establish links to other government.
Consumers will ultimately benefit from improvements to manufacturing underpinned by this innovative science. Understanding how this science positively benefits their lives is important if ground-breaking science of this kind is to be valued and supported in the future. The academic team will be responsible for distilling the key messages of the project into 'lay terms' accessible to the public. This will form the backbone of all communications with the public whether online, through print, at events or in presentations. Communicating these core messages will be the responsibility of all members of the consortium.

Publications

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