Microspacing In-Air Sublimation Growth of Organic Crystals

Organic single crystals manifest the intrinsic physical properties of materials. However, traditional growth of organic single crystals is limited by low solubility from solutions or complexity from physical vapor deposition. Here we report a new method to grow organic single crystals by microspacing in-air sublimation, which avoids costly vacuum system and time-consuming procedures and is practical for a wide range of organic crystals. In situ crystal growth observation revealed an unprecedented vapor-to-melt-to-crystal mechanism, resulting from the micrometer scale spacing distance between the source and the growth position. FET devices based on the rubrene crystals directly grown on Si/SiO<sub>2</sub> substrate exhibited higher mobility than the best record using SiO<sub>2</sub> as the gate dielectric. This effective organic crystal growth technique can be affordable and handled for almost every lab, which may be beneficial for future research and application of organic crystals.