Thermal Plasma Synthesis of Crystalline Gallium Nitride Nanopowder from Gallium Nitrate Hydrate and Melamine.
Gallium nitride (GaN) nanopowder used as a blue fluorescent material was synthesized by using a direct current (DC) non-transferred arc plasma. Gallium nitrate hydrate (Ga(NO₃)₃∙xH₂O) was used as a raw material and NH₃ gas was used as a nitridation source. Additionally, melamine (C₃H₆N₆) powder was injected into the plasma flame to prevent the oxidation of gallium to gallium oxide (Ga₂O₃). Argon thermal plasma was applied to synthesize GaN nanopowder. The synthesized GaN nanopowder by thermal plasma has low crystallinity and purity. It was improved to relatively high crystallinity and purity by annealing. The crystallinity is enhanced by the thermal treatment and the purity was increased by the elimination of residual C₃H₆N₆. The combined process of thermal plasma and annealing was appropriate for synthesizing crystalline GaN nanopowder. The annealing process after the plasma synthesis of GaN nanopowder eliminated residual contamination and enhanced the crystallinity of GaN nanopowder. As a result, crystalline GaN nanopowder which has an average particle size of 30 nm was synthesized by the combination of thermal plasma treatment and annealing.
Department of Chemistry and Chemical Engineering and Regional Innovation Center for Environmental Technology of Thermal Plasma (RIC-ETTP), Inha University, 100 Inha-ro, Nam-gu, Incheon 22212, Korea. taehee928@naver.com.
Tae-Hee
TH
Kim
Department of Nuclear and Energy Engineering, Jeju National University, 102 Jejudaehak-ro, Jeju 63243, Korea. sooseok@jejunu.ac.kr.
Sooseok
S
Choi
Department of Chemistry and Chemical Engineering and Regional Innovation Center for Environmental Technology of Thermal Plasma (RIC-ETTP), Inha University, 100 Inha-ro, Nam-gu, Incheon 22212, Korea. dwpark@inha.ac.kr.
Dong-Wha
DW
Park
annealing; gallium nitrate hydrate; gallium nitride; melamine; nanopowder; thermal plasma