Efficient silicon (Si)-compatible emitters can realize inexpensive light sources for a variety of applications. In this paper, we study both photonic crystal (PC) and plasmonic nanocavities that enhance the emission of Si-compatible materials. In particular, we examine the coupling of silicon nanocrystals (Si-NCs) to silicon nitride PC cavities and Si-NCs in silicon dioxide to plasmonic gratings, both for enhancement of emission in the visible wavelengths. In addition, we also observe the enhancement of the 1530 nm emission from erbium-doped silicon nitride films coupled to Si PC cavities. Finally, we analyze the loss mechanisms associated with the hybrid silicon nitride/silicon system, and propose advancements in the designs of PC and plasmonic cavities for the emitters described in this paper.