The Hamiltonian equation for positively charged exciton in double-layer harmonic quantum dots is solved numerically by using the exact diagonalization techniques. We find that the correlation energy Ec of positively c...The Hamiltonian equation for positively charged exciton in double-layer harmonic quantum dots is solved numerically by using the exact diagonalization techniques. We find that the correlation energy Ec of positively charged exciton increases with increasing the confinement strength and the binding energy decreases obviously for the heavy hole.展开更多
It is known experimentally that stable charged-exciton complexes can exist in low-dimensional semiconductor nanostructures. Much less is known about the properties of such charged-exciton complexes since three-body pr...It is known experimentally that stable charged-exciton complexes can exist in low-dimensional semiconductor nanostructures. Much less is known about the properties of such charged-exciton complexes since three-body problems are very difficult to be solved, even numerically. Here we introduce the correlated hyperspherical harmonics as basis functions to solve the hyperangular equation for negatively and positively charged excitons (trions) in a harmonic quantum dot. By using this method, we have calculated the energy spectra of the low-lying states of a charged exciton as a function of the radius of quantum dot. Based on symmetry analysis, the level crossover as the dot radius increases can be fully explained as the results of symmetry constraint.展开更多
报道了调制掺杂的ZnSe/BeTe/ZnSeⅡ型量子阱(type-ⅡQW)在低温(2—5K)条件下的光致发光(PL),光致发光激发(PLE)和磁性光致发光(magneto-PL)光谱的实验结果.观察到非掺杂样品的PL有两个很强的主发光峰而掺杂样品只有一个的奇异发光.PL直...报道了调制掺杂的ZnSe/BeTe/ZnSeⅡ型量子阱(type-ⅡQW)在低温(2—5K)条件下的光致发光(PL),光致发光激发(PLE)和磁性光致发光(magneto-PL)光谱的实验结果.观察到非掺杂样品的PL有两个很强的主发光峰而掺杂样品只有一个的奇异发光.PL直线偏振度和PLE的测量结果都表明了这些空间间接型跃迁PL是来自两个异质结界面的贡献,非掺杂样品的两个主发光峰的分离则是起因于QW结构中的内秉电场(built-in electric field).在平行于QW生长方向的强磁场中,掺杂样品的发光强度和主发光峰能量都显示了一个光学Shubinkov-de Hass(SdH)振荡.这些特征及另外的吸收光谱测量结果都表明,在掺杂样品中已经形成了一个高浓度的二维电子气;它具有type-ⅡQW所特有的带电激子的特征.展开更多
基金The project supported by the Natural Science Foundation of Guangdong Province under Grant No. 04009519 and National Natural Science Foundation of China under Grant No. 10475021
文摘The Hamiltonian equation for positively charged exciton in double-layer harmonic quantum dots is solved numerically by using the exact diagonalization techniques. We find that the correlation energy Ec of positively charged exciton increases with increasing the confinement strength and the binding energy decreases obviously for the heavy hole.
文摘It is known experimentally that stable charged-exciton complexes can exist in low-dimensional semiconductor nanostructures. Much less is known about the properties of such charged-exciton complexes since three-body problems are very difficult to be solved, even numerically. Here we introduce the correlated hyperspherical harmonics as basis functions to solve the hyperangular equation for negatively and positively charged excitons (trions) in a harmonic quantum dot. By using this method, we have calculated the energy spectra of the low-lying states of a charged exciton as a function of the radius of quantum dot. Based on symmetry analysis, the level crossover as the dot radius increases can be fully explained as the results of symmetry constraint.
文摘报道了调制掺杂的ZnSe/BeTe/ZnSeⅡ型量子阱(type-ⅡQW)在低温(2—5K)条件下的光致发光(PL),光致发光激发(PLE)和磁性光致发光(magneto-PL)光谱的实验结果.观察到非掺杂样品的PL有两个很强的主发光峰而掺杂样品只有一个的奇异发光.PL直线偏振度和PLE的测量结果都表明了这些空间间接型跃迁PL是来自两个异质结界面的贡献,非掺杂样品的两个主发光峰的分离则是起因于QW结构中的内秉电场(built-in electric field).在平行于QW生长方向的强磁场中,掺杂样品的发光强度和主发光峰能量都显示了一个光学Shubinkov-de Hass(SdH)振荡.这些特征及另外的吸收光谱测量结果都表明,在掺杂样品中已经形成了一个高浓度的二维电子气;它具有type-ⅡQW所特有的带电激子的特征.
