The Preparation Of The Large Size Of Zinc Oxide Crystals And Growth Mechanism

As a new wide and direct band-gap multifunctional Ⅱ-Ⅵ semiconductor material, zinc oxide has the advantages of excellent photoelectricity, electrical conduction, piezoelectricity, gas-sensitive and fine press-sensitive and so on. ZnO semiconductor's band-gap is 3.37eV at room temperature, and its bound exciton energy can be reach to 60MeV, which made it has great application value in ultraviolet semiconductor phototube. ZnO crystal growth technique has become a hot point in material research field because of the preparation difficulty and alluring application foreground. Our main task is seek after a compacting route, low cost, and easy operating preparation method for producing ZnO crystal.In this article we applied gas-transport method, used zinc ingot and atmosphere as raw material, discussed these factors such as oxidation time, airflow, N₂ flowing, zinc volatilization temperature, and oxidation temperature which influenced ZnO crystal growing, and we also made some primary discussion on growth mechanism. Controlling nucleation and growth process are two key roles to effect ZnO crystal growth, the two key roles are determined by process parameter which finally controlled the size of zinc oxide crystal.Research results:(1) Controlling nucleation and growth process are two key roles to effect large scale ZnO crystal growth, crystallizing structure of nucleation decided crystal configuration, atmospheric conditions and degree of gas-phase over saturate were also a factor influenced it.(2) When oxidation time was 90min, airflow was 0.31/min, nitrogen flow was 0.31/min, and zinc volatilization temperature was 1150℃ we got large scale ZnO crystal with the length of 30mm, which realized ZnO crystal controlling growth.(3) XRD result showed that the experimental product were completely ZnO, peak was peaky and narrow, which showed high degree of crystal. XRD pattern was accordance with JCPDS card number36-1451, and we(know) that the product was hexagonal structure ZnO, and crystal lattjeeconstant was a=0.3257nm, c=0.52156nm, in this paper we got ZnOcrystal with hexagonal ^incite structure (4) According to the photo of large scale ZnO crystal we knew crystal justlike a needle which indicated crystal growing in an orientation. FromXRD we knew (000/) was main growing direction which was just thesame as conventional +c axis growth mechanism.