【摘要】 采用第一性原理计算方法,通过改变Zn1-xBexO合金中Be的浓度及其掺杂位型,研究N在Zn1-xBexO合金中的形成能和受主离化能,分析了p型导电的可能性。结果表明:Be-N共掺杂时,N优先占据周围没有Be的O位置,每增加一个Be近邻掺杂原子,NO的形成能增加约0.2 eV。当近邻Be原子数为2和3时,NO的受主离化能比较低。Be浓度为11at%时,具有2个近邻Be原子的NO的受主离化能降低至0.1 eV左右,可以认为是浅受主,Be-N共掺ZnO才可能呈p型导电。考虑NO在室温条件下的受主离化率和NO形成能的影响,估算出Be-N所提供的空穴载流子浓度不会高于1017cm-3;如果计及n型背景载流子的补偿效应,Be-N共掺ZnO的p型导电率应该比较低。更多还原

【Abstract】 Using the first-principles methods on the basis of density functional theory,the formation energy and acceptor ionization energy of N substituting for O site( NO) in Zn1-xBexO alloy by changing the Be concentration and configurations were calculated. The calculations of the formation energy of NOin Zn1-xBexO alloy suggest nitrogen atoms are preferred to substitute the oxygen sites without the nearest neighbor Be doping atoms. The formation energy of NOwill increase about 0. 2 eV for per nearest neighbor Be atom. The ionization energy of NOacceptor is also related to the nearest neighbor doping atoms. For Zn1-xBexO alloys,the NOacceptors with 2 nearest neighbor Be atoms have the lowest ionization energy,about 0. 1 eV,indicating the NOacceptors can be regarded as the low acceptors and the corresponding Be content is about 11% with the results of formation energy and ionization energy of NOin Zn1-xBexO alloy. At the given Be content( 11%),Be-N co-doping could realize the p-type conductivity,but the carrier concentration is not expected to be high enough.更多还原