<p>The miniaturization of optical devices with the advancement of micro/nano technology has led to the development of many research fields and various practical applications. Plasmonic nanolasers have attracted a lot of attention due to their ability to confine light in dimensions below the diffraction limit as well as the significant reduction of semiconductor laser dimensions. However, plasmonic nanolasers have a low quality factor due to plasmonic losses, which limits the performance of plasmonic nanolasers. In this paper, a hybrid plasmonic nanolaser with a structure consisting of GaP gain material, silver metal, graphene layer, silica, and air gap is designed, and by choosing different gain materials such as InP, WS₂, MoS₂, and MoTe₂, the effective refractive index and quality (<i>Q</i>) factor are simulated. Also, the effect of air gap on the mentioned parameters is investigated. The results show that by choosing the WS₂ material for the hybrid plasmonic nanolaser and the air gap dimensions of 25 nm width and 10 nm length, the maximum <i>Q</i> factor of 328.7 is obtained which is higher than those reported in the literature.</p>