Spectral Tuning of Quantum Emitters in Graphene/hBN heterostructures

Hexagonal Boron Nitride (hBN) is a representative wide-bandgap two-dimensional material. Some point defects in hBN host single photon emissions (SPEs). Defects in hBN are regarded as a promising source of SPEs due to their advantageous properties such as bright intensity, high purity, and room-temperature operation. The spectral peak position of emission is one of the important characteristics of SPEs. Recently, using a graphene/hBN heterostructure, SPEs can be turned on and off by transferring charges from graphene to non-radiative defect states in hBN. In our study, we explored the methods to control the spectral peak positions of SPEs in graphene/hBN heterostructures. We observed an unconventional peak energy shift of SPEs after exposure to a blue laser, which is related to the ionization of local defects. We developed a protocol to control this process using graphene/hBN heterostructures and achieved stable control of SPEs. We hope this study provides new insights for quantum applications of single-photon emitters in two-dimensional materials.