Topological attributes and photo-dynamics of visible spectrum quantum emitters in hexagonal boron nitride

Nathan Chejanovsky, Mohammad Rezai, Federico Paolucci, Youngwook Kim, Torsten Rendler, Wafa Rouabeh, Felipe Fávaro de Oliveira, Patrick Herlinger, Andrej Denisenko, Sen Yang, Ilja Gerhardt, Amit Finkler, Jurgen H. Smet, Jörg Wrachtrup

Published 2016-08-10Version 1

Newly discovered van der Waals materials like MoS$_2$, WSe$_2$, hexagonal boron nitride (h-BN) and recently C$_2$N have sparked intensive research to unveil the quantum behavior associated with their 2D topology. Of great interest are 2D materials that host single quantum emitters. h-BN, with a band-gap of 4.6 - 7 eV, has been shown to host single quantum emitters which are stable at room temperature in the UV and visible spectral range. In this paper we investigate correlations between h-BN topological features and emitter location from bulk down to the mono-layer at room temperature. We demonstrate that chemical etching and ion irratiation can generate emitters in h-BN. We analyze the emitters' spectral features and show that they are dominated by the interaction of the electronic transition with single Raman active mode of h-BN. Photo-dynamics analysis reveals diverse rates between the electronic states of the emitter. The emitters show excellent photo stability even under ambient conditions and in monolayers. Comparing the excitation polarization between different emitters unveils a connection between defect orientation and the h-BN hexagonal structure. The sharp spectral features, color diversity, room-temperature stability, long lived meta-stable states, ease of fabrication, proximity of the emitters to the environment, outstanding chemical stability and bio-compatibility of h-BN provide a completely new class of systems that can be used for sensing and quantum photonics applications.