Emerging flexible heterojunctions: fabrication, properties and optoelectronic applications

Flexible heterojunctions have attracted increasing attention in recent years due to their multifunctionality and exceptional advantages for optoelectronic applications, such as mechanical compliance, dimensional freedom and strain tunability. With the rapid development of flexible heterojunctions, a comprehensive view of assembly strategies for their generation and regulation with precise control is highly desirable. In this perspective, we systematically summarize recent key advances in flexible heterojunctions from various aspects, including their classification, assembly strategies and representative applications. We also highlight the effect of the underlying structure-property relationship on the performance of flexible heterojunctions, particularly in systems of small molecules, polymers and inorganic-organic hybrids. Our aim is to bring together pieces of research from fundamental discoveries of flexible heterojunctions to their properties under different application backgrounds. Finally, we propose the current issues and future trends to provide new ideas for continuous improvement in this field.