Electron-hole interactions in silicon nanocrystals
Electron-hole interactions in silicon nanocrystals
复制标题
硅纳米晶中的电子-空穴相互作用
DOI：
10.1103/physrevb.56.7455
复制
发表时间：
1997
影响因子：
3.7
通讯作者：
K. B. Whaley
中科院分区：
文献类型：
--
作者：
K. Leung;K. B. Whaley
我们研究了球形硅纳米晶体中的电子-空穴相互作用，将库仑，交换和自旋轨道耦合到一个紧束缚模型。我们研究了吸收光谱和介电常数上的电子空穴吸引的效果，使用实时传播技术。对角化的完整的精细结构的哈密顿两粒子状态接近的带隙给出交换分裂的范围从{approximately}100至7毫电子伏的半径为6{endash}18 {埃}的纳米晶体。分裂坚持在存在的自旋-轨道耦合的纳米晶体的半径高达18 {埃}，这表明，黑暗的三重态低于吸收阈值可以是起源的斯托克斯位移和温度依赖的发光实验中观察到的寿命。{版权} {美国物理学会}
We investigate the electron-hole interactions in spherical silicon nanocrystals by incorporating Coulomb, exchange, and spin-orbit couplings into a tight-binding model. We study the effect of the electron-hole attraction on the absorption spectra and on the dielectric constant, using a real-time propagation technique. Diagonalizing the full fine-structure Hamiltonian for two-particle states close to the band gap gives exchange splittings that range from {approximately}100 to 7 meV for nanocrystals of radii 6{endash}18 {Angstrom}. The splittings persist in the presence of spin-orbit coupling for nanocrystals of radius up to 18 {Angstrom}, suggesting that dark triplet states below the absorption threshold can be the origin of the Stokes shifts and temperature-dependent lifetimes observed in luminescence experiments. {copyright} {ital 1997} {ital The American Physical Society}