Defect-based quantum emitters in aluminum nitride-passivated silicon carbide*

Silicon carbide (SiC) hosts several defect-based single photon emitters, making it particularly useful for applications in quantum technology. In order to enhance the signal coming from these quantum emitters, the SiC host is often nanostructured. This can result in the proximity of quantum emitters to the surfaces of SiC. In a recent work [1], we showed that a near-surface defect in SiC can lose its photostability due to surface effects.  In principle, this issue can be remedied by uniform passivation of the dangling bonds on the surface with a suitable adsorbate, such as hydrogen or the mixed hydrogen/hydroxyl groups. However, these passivation schemes may not be reliable in the long-term due to their limited chemical and/or thermal stability [2]. In this first principles study, we employ an AlN/SiC core shell nanowire to study how passivation with an AlN layer affects different properties of SiC defects. Interestingly, we find that our proof-of-principle defect, the negatively charged silicon vacancy, has very different properties when created at the interface versus when created in the SiC core.

 

References:

 

[1] T. Joshi and P. Dev, “Site-Dependent Properties of Quantum Emitters in Nanostructured Silicon Carbide,” PRX Quantum 3, 020325 (2022)

 

[2] M. J. Polking, A. M. Dibos, N. P. de Leon, and H. Park, “Improving Defect-Based Quantum Emitters in Silicon Carbide via Inorganic Passivation,” Adv. Mater. 30, 1704543 (2018).