SCIENCE SPIN-OFFS

[dockzef]

Two-dimensional (2D) materials have recently emerged as a promising platform for optoelectronics[1] and nanophotonics[2] owing to their atomically thin lattice structure and weak van der Waals interlayer interactions. Among these layered materials, transition metal dichacogenides (TMDs) such as molybdenum disulfide (MoS2), tungsten disulfide (WS2), molybdenum diselenide (MoSe2), and tungsten diselenide (WSe2) have garnered the most research interest thanks to their direct bandgaps (for monolayers), large carrier mobility, gate-tunability and mechanical flexibility.[3] The recent discoveries of single photon sources in the form of quantum dots in WSe2[4] and MoSe2[5] have further spurred intensive research into the use of TMDs for quantum information and processing. The 2D nature of these crystals and the know-how gained from work on manipulation of graphene, enabled rapid engineering of electrically triggered quantum light emitting diodes[6]
However, due to the shallow binding energies of several millielectron volts (meV), these quantum dots exhibit single photon emission only at cryogenic temperature. Furthermore, the nature of the quantum emitters is still under debate and their spectral filtering is challenging due to close proximity to excitonic lines of the host materials. On the other hand, room temperature (RT) single photon emission was recently observed from monolayers, few layers and bulk hexagonal boron nitride (hBN)[7, 8]. hBN has a wide bandgap of almost 6 eV and can therefore host a variety of localized defects with deep states that enable single photon emission at room temperature. In this letter, we report on quantum emission observed from annealed WS2 multilayers. We show that annealing at a temperature of 550°C gives rise to partial oxidation of the flakes and to formation of localized stable optically active defects. We characterize the nature of the emissions and propose several models for the origin of the emitters.

Room temperature single photon emission from oxidized tungsten disulphide multilayers

Toan Trong Tran,1,* Sumin Choi,1 John A. Scott, 1 Zai-quan Xu, 1 Changxi Zheng,2, 5 Gediminas Seniutinas,1 Avi Bendavid,3 Michael S. Fuhrer,4, 5 Milos Toth1,^ and Igor Aharonovich1

T. T. Tran, S. Choi, John A. Scott, Dr. Zaiquan Xu, Dr. G. Seniutinas, Prof. M. Toth, Prof. I. Aharonovich School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, NSW, 2007, Australia

E-mail: [e-mail]

Dr. C. Zheng Department of Civil Engineering, Monash University, Clayton, VIC, 3800, Australia

Dr. A. Bendavid Plasma Processing & Deposition Team, CSIRO Manufacturing Flagship, Australia

Prof. M. S. Fuhrer School of Physics and Astronomy, Monash University, Clayton, VIC, 3800, Australia

Dr. C. Zheng, Prof. M. S. Fuhrer Monash Centre for Atomically Thin Materials, Monash University, Clayton, VIC, 3800, Australia

https://arxiv.org/ftp/arxiv/papers/1701/1701.00041.pdf