Synthesis and Growth Techniques

Various synthetic approaches have been applied to obtain stable and metastable Ga203 polymorphs, as either bulk crystalline phases or nanoparticles. Single crystals of the thermodynamically stable P-Ga203 phase can be obtained with and without dopants by using the Verneuil method, under oxidizing and reducing atmospheres [183,184]. 

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In the past, several reviews have summarized the different synthesis and growth techniques developed to improve the degree of crystallinity of GaN films or the bulk phase [43, 105, 130, 132-137]. The two main categories of preparation methods address diEFerent aims of appUcations the first concerns the epitaxial deposition of highly ordered films on substrates for blue LEDs or lasers the second other focuses on the growth of large single crystals for use as substrates or wafers. In both cases the main problem is the decomposition of GaN under elevated temperatures. 

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