One-step synthesis of single-crystal Si3N4 nanowires-amorphous SiO2 beads nanochains by chemical vapor deposition

Abstract

One-dimensional (1D) nanochain heterojunctions have attracted wide attention due to their unique optical and electrical properties, while efficient and controllable synthesis of nanochains is still difficult. Herein, Si3N4/SiO2 nanochain heterojunctions (Si3N4 single-crystal nanowires and amorphous SiO2 beads) were successfully synthesized by a one-step chemical vapor deposition (CVD) process without using any templates and catalysts. A two-stage growth mode was proposed to explain the formation mechanism of the special nanochain. We found that carbon vapor induced the formation of Si3N4 nanowires and suppressed the formation of Si2N2O. The Si3N4/SiO2 nanochains can only be synthesized within a suitable concentration range of carbon vapor. The as-synthesized fascinating nanochain exhibits an extra strong emission at about 3.02 eV, showing great promise for optoelectronic nanodevices.