Narrow-band photoluminescence at room-temperature in amorphous SiCx:H film

We report strong narrow-band photoluminescence at room temperature in amorphous SiCx:H films synthesized by means of high-density reactive plasma. The emission energy is found to remain constant with varying nanoparticle sizes. Detailed bond configuration analysis shows that the PL intensity strongly depends on the density of nanoparticle and Si–C bonds. On the basis of a variety of bond characterizations, the origin of photoluminescence is explained as two separated processes: photoexitation in Si nanoparticles embedded in amorphous SiC matrix and photoemission in SiC matrix or at Si/SiC interface. The contribution from the passivation behavior of amorphous SiC on Si nanoparticle surface is also proposed.

► Method of low frequency inductively coupled plasma is used to deposit SiCx:H.
► PL peak location doesn’t change with the reduction of the nanoparticle size.
► A new PL mechanism different from quantum size effect is proposed.
► Relationship between the chemical bond and PL intensity is constructed.