采用第一性原理模拟计算纤锌矿结构GaN半导体中InN量子点的结构性质。建立64和128个原子的超原胞量子点模型,进行结构优化以获得稳定的吻合实际的系统,并模拟分析电子结构。从态密度空间分布图看到不同轴向的量子势阱形状各异、深度不一,说明量子点的限域效应存在着各向异性的特点。c轴极化方向引起量子点结构带边的弯曲形状与传统的量子阱结构不同,使得电子空穴没有发生空间分离,有利于电子空穴的跃迁几率的提高。Using the first-principles calculation with 64 and 128 atom supercells the geometric and electronic structures of InN quantum dots(QDs)embedded in wurtzite GaN were simulated.After optimizing the stress and total energies,electronic structures of the stable systems were further calculated.The electronic densities of states show distinguishing quantum-confine-effects along different axes.Moreover,the curves of energy band edge appear in InN QDs.Compared with the typical band-edge shape of quantum well under the polarization that leads to the separation of electrons and holes in space,we found that the separation problem could be eliminated due to the curves of energy band edge in QDs,which is favourable for enhancement of the transition probability of the electrons and holes.国家“973”计划(001CB610505);; 国家“863”计划(2006AA03A110);; 国家基础研究计划(001CB610505);; 国家自然科学基金(90206030,60376015,60336020,10134030)资助项目~
