Manufacturing Organic-Inorganic Nanoparticle Composites with Nanoscale Precision via Directed Self-Assembly

New optoelectronically and photonically active materials - such as organic semiconductors and nanoparticles - are bringing to market new technologies and products such as organic light-emitting diodes (OLEDs) and new phosphors (as used in QD TVs and LED white lighting). Our understanding of the fundamental properties of these materials as well as the rate of design of new materials is accelerating. Of particular interest is a new generation of systems combining organic semiconductors with inorganic nanoparticles. These hybrid blends or nanocomposites hold great promise as a platform technology for high-efficiency low-cost solar energy harvesting devices, photodetectors and novel LEDs for displays, communications and chemical diagnostics.

A scalable manufacturing process for these materials will rely on solution processing of an ink comprising the organic semiconductor, the nanoparticles and a suitable solvent to produce a functional film or coating. However, the components of these organic-nanoparticle blends have a strong tendency to aggregate and phase separate during solution processing, due to a mismatch of their size, shape and surface energies1. This severely compromises device performance and to date has ruled out the manufacture of these systems via large-area-compatible solution manufacturing techniques such as bar-coating, slot-die coating or inkjet printing. Our proposed methodology will overcome these problems, demonstrating routes by which the two active components spontaneously self-assemble during deposition and subsequent solvent evaporation to yield a nanocomposite with a precise morphology and structure over the hierarchy of length scales described above. Thus, our proposal directly tackles the challenge of achieving the precision manufacture at scale of functional nanocomposites. We seek to develop new molecular engineering methodologies providing a toolkit of manufacturing approaches enabling precise control over a hierarchy of length scales. This will create manufacturing routes a new generation of optoelectronically and photonically active coatings and films based on organic-nanoparticle blends, accelerating the translation of fast-moving developments in the physics and chemistry of these hybrid materials into economic benefit for the UK and benefits to society world-wide.