电场对InAs/InAlAs圆形截面量子线中激子态的影响

Effects of Electric Field on Exciton States in InAs/InAlAs Circular Cross Section Quantum Wires

基于有效质量包络函数近似理论,采用变分法计算了InAs/In_(x)Al_(1-x)As圆形截面量子线中的基态激子结合能和发射能。计算过程主要考虑了量子线半径、材料组分和外加电场的影响。理论研究表明,随着量子线半径的减小,激子结合能先增大到最大值,然后继续减小;Al组分越高,激子的结合能越高;较小强度的外加电场对激子结合能影响不大,而较大强度的外加电场会破坏激子效应。此外,还发现较大的量子线半径对电场更敏感。发射能与量子线半径、电场强度之间呈非线性关系,发射能随半径或电场的增大而减小。

Based on the effective mass envelope function approximation theory,the ground state exciton binding energy and emission energy in InAs/InxAl1-xAs circular cross section quantum wires are calculated by using the variational method.The calculation process mainly considers the influence of quantum wire radius,material composition and applied electric field.Theoretical research shows that as the radius of the quantum wire decreases,the exciton binding energy first increases to the maximum value,and then continues to decrease;The higher the Al composition,the higher the binding energy of excitons;The applied electric field with small intensity has little effect on the exciton binding energy,while the applied electric field with large intensity will destroy the exciton effect.In addition,it is also found that the larger quantum wire radius is more sensitive to the electric field.The relationship between the emission energy and the radius of the quantum wire and electric field is nonlinear,and the emission energy decreases with the increase of the radius or electric field.