We study the energy spectra of a two-dimensional two-electron quantum dot （QD） with P6schl-Tefler confining potential under the influence of perpendicular homogeneous magnetic field. Calculations are made by using t...We study the energy spectra of a two-dimensional two-electron quantum dot （QD） with P6schl-Tefler confining potential under the influence of perpendicular homogeneous magnetic field. Calculations are made by using the method of numerical diagonalization of Hamiltonian matrix within the effectlve-mass approximation. A ground-state behavior （spin singlet-triplet transitions） as a function of the strength of a magnetic field is found. We find that the dot radius R of a Poeschl-Teller potential is important for the ground-state transition and the feature of ground-state for a Poeschl Teller QD and a parabolic QD is similar when R is larger. The larger the well depth, the higher the magnetic field for the singlet-triplet transition of the ground-state of two interacting electrons in a Poesehl-Teller QD.展开更多
为了研究红荧烯（5,6,11,12-tetraphenylnaphthacene,Rubrene）器件中三重态激子与电荷相互作用的微观过程,制备了基于Rubrene的有机发光二极管,并测量了室温下器件的磁电导（magneto-conductance,MC）.实验发现,器件MC曲线的幅值非常...为了研究红荧烯（5,6,11,12-tetraphenylnaphthacene,Rubrene）器件中三重态激子与电荷相互作用的微观过程,制备了基于Rubrene的有机发光二极管,并测量了室温下器件的磁电导（magneto-conductance,MC）.实验发现,器件MC曲线的幅值非常小且表现出了奇特的变化：即在0-8 m T的磁场范围内,MC随磁场快速增大;当磁场处于8-100 m T时,MC则表现为下降;但当磁场大于100 m T时,MC则表现为缓慢增加.分析发现,Rubrene器件中除了超精细相互作用外,还有空穴对三重态激子的解离作用和三重态激子对电子的散射作用的共存,且它们都受单重态激子分裂（singlet fission）的影响.利用Lorentzian和non-Lorentzian经验函数可以对MC进行较好拟合,进一步证实了上述观点.三重态激子解离和电子散射共存这一发现不仅有助于对Rubrene器件中电荷与激发态间相互作用机制的认识,在优化器件性能方面也有一定的指导意义.展开更多
基金The project supported by National Natural Science Foundation of China under Grant No. 10475021
文摘We study the energy spectra of a two-dimensional two-electron quantum dot （QD） with P6schl-Tefler confining potential under the influence of perpendicular homogeneous magnetic field. Calculations are made by using the method of numerical diagonalization of Hamiltonian matrix within the effectlve-mass approximation. A ground-state behavior （spin singlet-triplet transitions） as a function of the strength of a magnetic field is found. We find that the dot radius R of a Poeschl-Teller potential is important for the ground-state transition and the feature of ground-state for a Poeschl Teller QD and a parabolic QD is similar when R is larger. The larger the well depth, the higher the magnetic field for the singlet-triplet transition of the ground-state of two interacting electrons in a Poesehl-Teller QD.
文摘为了研究红荧烯（5,6,11,12-tetraphenylnaphthacene,Rubrene）器件中三重态激子与电荷相互作用的微观过程,制备了基于Rubrene的有机发光二极管,并测量了室温下器件的磁电导（magneto-conductance,MC）.实验发现,器件MC曲线的幅值非常小且表现出了奇特的变化：即在0-8 m T的磁场范围内,MC随磁场快速增大;当磁场处于8-100 m T时,MC则表现为下降;但当磁场大于100 m T时,MC则表现为缓慢增加.分析发现,Rubrene器件中除了超精细相互作用外,还有空穴对三重态激子的解离作用和三重态激子对电子的散射作用的共存,且它们都受单重态激子分裂（singlet fission）的影响.利用Lorentzian和non-Lorentzian经验函数可以对MC进行较好拟合,进一步证实了上述观点.三重态激子解离和电子散射共存这一发现不仅有助于对Rubrene器件中电荷与激发态间相互作用机制的认识,在优化器件性能方面也有一定的指导意义.
