Optoelectronics based on novel molecular combinations
Thin-film metal oxides are a growing trend in the electronics industry in its effort to make smaller, lighter-weight and higher-performance devices. The oxides are deposited in a way that facilitates crystal growth in an organised way. The latest trend is the use of metal oxide nanostructures and their versatile application to such diverse fields as sensors, batteries, solar cells and energy storage. European researchers formed a consortium consisting of leading scientists in supramolecular (based on assemblies of two or more molecules) photochemistry, nano-structured inorganic materials science and optoelectronic device physics. Their goal was to develop novel supramolecular devices for integration into nanocrystalline metal oxide electrodes. With EU-funding of the ‘Nanocrystalline heterosupermolecular materials for optoelectronic applications’ (Heteromolmat) project, the consortium pursued development of three innovative heterosupramolecular (based on two or more different molecules) devices: hybrid light-emitting diodes (HyLEDs), light-coupled chemical sensors and near-infrared (NIR) light-to-energy conversion devices. HyLEDs using metal oxides have numerous advantages over standard LEDs and strictly organic LEDs. Metal oxide technology encompasses many technical benefits as well as low-cost mass production. HyLEDs were developed that demonstrated increased efficiency and should provide an attractive alternative to organic LEDs. Heteromolmat scientists successfully designed and synthesised supramolecular structures capable of ‘recognising’ specific toxic substances such as mercury in a sample. The molecules bound easily to metal oxide films thanks to specially incorporated binding groups. Interaction of supramolecular structures with the toxic substance changed the optical properties of the molecules resulting in a light-coupled chemical sensor. Finally, researchers made record-breaking NIR solar-to-electric energy conversion devices based on the synthesis of novel supramolecular NIR dyes. The solar energy field is poised for a revolution given the tremendous amount of energy available and the minimal amount currently exploited. Perhaps it will get a boost from Heteromolmat technology. The Heteromolmat consortium with interdisciplinary expertise was able to develop important nanocrystalline supramolecular semiconductor materials. They applied these materials with great success to optoelectronic devices including LEDs, light-emitting chemical sensors and light-to-electrical energy conversion devices. Using low-cost and easily scalable metal oxide semiconductor technology as a foundation, the innovations are poised for rapid commercialisation.
