Solution Processing of Functional Thin Films and Their Device Applications

Abstract

Solution processing of thin films is a key energy-saving technology for sustainable development. Not only for its cost advantages, but it can achieve materials with unique structures and new functionalities through the combination of earth-abundant elements, especially by their hybridization with organic molecules. As the process relies on mild activation, such as low-temperature heating and irradiation with ultraviolet light having high photon energy, it is compatible with plastic film substrates. This compatibility makes it suitable for roll-to-roll mass production of flexible optoelectronic devices with large areas at a low cost. Herein, we present a review of our recent progress in the low-temperature solution processing of inorganic/organic hybrid thin films with various functionalities, including thin film encapsulation (TFE) to protect organic light-emitting diodes (OLEDs) from moisture for long-lasting operation, color-tunable photoluminescent nanocrystalline ZnO core-organic shell hybrids, and an energy-selective electron injection layer (EIL) for highly efficient inverted OLEDs. While general concept, methodology and challenges of solution processing are summarized, the future of the related technology is scoped for our sustainable development.