Open Access Nano Express

Crystalline Gaq3Nanostructures: Preparation, Thermal Property and Spectroscopy Characterization

Ya-Wen Yu1, Chun-Pei Cho2 and Tsong-Pyng Perng13*

Author Affiliations

1 Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, 30013, Taiwan

2 Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Nantou, 54561, Taiwan

3 Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-Li, 32003, Taiwan

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Nanoscale Research Letters 2009, 4:820-827  doi:10.1007/s11671-009-9321-y

Published: 30 April 2009

Abstract

Crystalline Gaq31-D nanostructures and nanospheres could be fabricated by thermal evaporation under cold trap. The influences of the key process parameters on formation of the nanostructures were also investigated. It has been demonstrated that the morphology and dimension of the nanostructures were mainly controlled by working temperature and working pressure. One-dimensional nanostructures were fabricated at a lower working temperature, whereas nanospheres were formed at a higher working temperature. Larger nanospheres could be obtained when a higher working pressure was applied. The XRD, FTIR, and NMR analyses evidenced that the nanostructures mainly consisted of δ-phase Gaq3. Their DSC trace revealed two small exothermic peaks in addition to the melting endotherm. The one in lower temperature region was ascribed to a transition from δ to β phase, while another in higher temperature region could be identified as a transition from β to δ phase. All the crystalline nanostructures show similar PL spectra due to absence of quantum confinement effect. They also exhibited a spectral blue shift because of a looser interligand spacing and reduced orbital overlap in their δ-phase molecular structures.

Keywords:
Gaq3; 1-D nanostructures; Nanospheres; Thermal evaporation; Crystallization; Phase transition