Ag-N共掺杂ZnO电子结构的理论研究

Study on Electronic Structure of Ag-N Co-doped ZnO

摘要:

采用基于DFT理论的第一性原理方法研究了Ag-N共掺杂纤锌矿ZnO的晶格结构和电子结构, 计算了包括共掺杂体系的晶格常数、杂质形成能和电子态密度等性质。研究结果显示, 共掺改善了杂质原子对体相晶格结构的扰动, 提高了掺杂的稳定性。此外, 电子结构的计算表明共掺形成的受主能级较单掺时更浅, 且空穴态的局域性降低, 从而改善了p型ZnO的传导特性, 表明受主共掺可能是一种比较有潜力的p型ZnO掺杂方式。计算与实验结果符合, 为受主共掺形成p型ZnO的机理提供了理论支持。

Abstract:

The crystal and electronic structure, involving the crystal lattice, impurity formation energy, as well as density of states, of Ag-N codoped wurtzite ZnO were simulated and then calculated by using the first-principles based on the density functional theory (DFT),. The results show that codoping minimizes the changes of lattice constants resulted form the impurity atoms and improved the stability of the dopant. Besides, Ag-N codoping can form a shallower acceptor level and higher acceptor densities. Furthermore, the nonlocalization of hole carriers is enhanced, the conductivity characters of the p-type ZnO is therefore improved, indicating that the dual-acceptor codoping may be a promising way for generating p-type ZnO. The calculations compare well with the experimental results, which thus provide theoretical support to the formation mechanism of dual-acceptor induced p-type ZnO.