Synthesis of GaN Nanocrystals through Phase Transition from Hexagonal to Cubic Structures upon Laser Ablation in Liquid

Abstract

The phase transition from hexagonal to cubic GaN has been observed upon pulsed-laser ablation of hexagonal GaN powders in a liquid at room temperature and ambient pressure. At the same time, GaN nanocrystals are synthesized through this hexagonal-to-cubic phase transition. Cathodoluminescence spectroscopy is employed to characterize the luminescence of the synthesized GaN nanocrystals. First-principle calculations are used to clarify the physical and chemical mechanisms of the phase transition from hexagonal to cubic GaN upon pulsed-laser induced solid–liquid interface reaction.

Midrefractive Dielectric Modulator for Broadband Unidirectional Scattering and Effective Radiative Tailoring in the Visible Region

“…In addition, the resonant modes in MRMs covering the visible range are stable and intrinsic, and possess low nonradiative damping compared with those of conventional plasmonic materials. A series of MRM nanospheres composed of materials such as boron (B), silicon carbide (SiC), aluminum nitride (AlN), and zinc oxide (ZnO) are fabricated through a convenient bottom-up technique based on laser-induced ablation in a liquid, − and demonstrated to possess intrinsic broad modes. , Taking B nanospheres as a typical example of MRMs, we demonstrate that a single B nanosphere can behave as a new broadband unidirectional nanoantenna, radiating a light signal on almost only one side in the visible region because of an internal broadband electromagnetic interaction …”

Generation of InN nanocrystals in organic solution through laser ablation of high pressure chemical vapor deposition-grown InN thin film

“…Another promising method for nanoparticle generation is the laser ablation method (Mafune et al 2000a(Mafune et al , b, 2001Niu et al 2010;Hong et al 2003). The use of unique scientific facilities of laser-matter interaction properties opens the door to the generation of a wide variety of noble nanoparticles (Amendola and Meneghetti 2009;Deniz et al 2011;Sylvestre et al 2004), semiconductor nanocrystals (Švrček et al 2006;Yang et al 2008;Kuzmin et al 2010, Liu et al 2008aIntartaglia et al 2011), nitride, metal and metal oxide nanocrystals (Liu et al 2008b;Nishi et al 2010;He et al 2007). Compared to other nanostructure synthesis methods, laser ablation, especially in liquids, is a versatile method of generating colloidal, highly pure, and agent-free nanocrystals.…”

Synthesis of blue-shifted luminescent colloidal GaN nanocrystals through femtosecond pulsed laser ablation in organic solution

“…The power density in the order of 10 8 W/cm 2 in our experiment corresponds to the lower limit of the vapor and plasma generation range (Zeng et al 2012). The resultant NPs are smaller in size compared to the ones in Liu et al (2008) work in which two orders of magnitude with higher power density applied.…”

“…Due to the quantum confinement effect, blue shifts were observed in both absorption and PL spectra. Liu et al (2008) synthesized GaN-NCs with the size distribution in the range of 50-150 nm via nanosecond laser ablation in ethanol. They observed phase transition from hexagonal to hexagonal-cubic crystal structures.…”