Carrier Generation in Multicomponent Wide-Bandgap Oxides: InGaZnO4

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• 作者：Altynbek Murat ; Alexander U. Adler ; Thomas O. Mason ; Julia E. Medvedeva
• 刊名：The Journal of the American Chemical Society
• 出版年：2013
• 出版时间：April 17, 2013
• 年：2013
• 卷：135
• 期：15
• 页码：5685-5692
• 全文大小：394K
• 年卷期：v.135,no.15(April 17, 2013)
• ISSN：1520-5126

文摘

To exploit the full potential of multicomponent wide-bandgap oxides, an in-depth understanding of the complex defect chemistry and of the role played by the constituent oxides is required. In this work, thorough theoretical and experimental investigations are combined in order to explain the carrier generation and transport in crystalline InGaZnO₄. Using first-principles density functional approach, we calculate the formation energies and transition levels of possible acceptor and donor point defects as well as the implied defect complexes in InGaZnO₄ and determine the equilibrium defect and electron densities as a function of growth temperature and oxygen partial pressure. An excellent agreement of the theoretical results with our Brouwer analysis of the bulk electrical measurements for InGaZnO₄ establishes the Ga antisite defect, Ga_Zn, as the major electron donor in InGaZnO₄. Moreover, we show that the oxygen vacancies, long believed to be the carrier source in this oxide, are scarce. The proposed carrier generation mechanism also explains the observed intriguing behavior of the conductivity in In-rich vs Ga-rich InGaZnO₄.