title: Photoluminescence and electronic transitions in cubic silicon nitride.
abstract: A spectroscopic study of cubic silicon nitride (γ-Si3N4) at cryogenic temperatures of 8 K in the near IR - VUV range of spectra with synchrotron radiation excitation provided the first experimental evidence of direct electronic transitions in this material. The observed photoluminescence (PL) bands were assigned to excitons and excited and centers formed after the electron capture by neutral structural defects. The excitons are weakly quenched on neutral and strongly on charged defects. The fundamental band-gap energy of 5.05 ± 0.05 eV and strong free exciton binding energy ~0.65 eV were determined. The latter value suggests a high efficiency of the electric power transformation in light in defect-free crystals. Combined with a very high hardness and exceptional thermal stability in air, our results indicate that γ-Si3N4 has a potential for fabrication of robust and efficient photonic emitters.
authors.affiliation: Laboratoire de Physique des Lasers, CNRS, Université Paris 13, Sorbonne Paris Cité, 93430 Villetaneuse, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Museur
authors.affiliation: Laboratoire des Sciences des Procédés et des Matériaux, CNRS, Sorbonne Paris Cité, Université Paris 13, 93430 Villetaneuse, France.
authors.forename: Andreas
authors.initials: A
authors.lastname: Zerr
authors.affiliation: Laboratoire des Sciences des Procédés et des Matériaux, CNRS, Sorbonne Paris Cité, Université Paris 13, 93430 Villetaneuse, France.
authors.forename: Andrei
authors.initials: A
authors.lastname: Kanaev