Single molecule spectroscopy of emitters encapsulated under hexagonal boron nitride.

Organic light-emitting molecules are attractive materials for applications in optoelectronics due to their strong light-matter interaction and high quantum yield, and the possibility to engineer their properties through organic synthesis. However, photostability under ambient conditions remains a key challenge, with photobleaching and photoblinking commonly limiting device performance. In this study, we demonstrate that the photostability of such molecules can be significantly improved by encapsulating organic emitters under hexagonal boron nitride. We spectroscopically study single TIPS-pentacene molecules deposited on glass substrates and covered with hexagonal boron nitride and find that they exhibit photobleaching times exceeding two hours. In comparison, identical molecules deposited on bare glass surfaces without encapsulation typically bleach within a hundred seconds. Our work is a step on the route of fully embedding single molecule emitters in van der Waals materials and using this stack to integrate the emitters into nanostructures or interfacing them to electric or magnetic fields.