A ring dark soliton is a two-dimensional dark soltion occurring in higher dimensions. We find that a stable RDS cannot exist without a defect. We then propose a way to create a stable RDS by adding a radial Gaussian defect to system. A RDS pinned by the defect potential becomes stable. For various pump powers, we investigate the stable regions of the RDS by tuning the strength and width of the defect potential. Numerical results show that the polaritonic RDSs can be stabilized in a suitable interval of defect potential strengths and pump powers.
