摘要
Artificial modulation of electronic structures and control of the transport dynamics of carriers and excitons in Cd Se nanowire are important for its application in optoelectronic nanodevices. Here, we demonstrate the aggregative flow of excitons by bending Cd Se nanowires. The bending strain induces spatial variance of bandgap, and the energy bandgap gradient will result in the flow of excitons towards the bending outer edge of Cd Se nanowire. The exciton emission energy shows a uniform redshift in the bending region due to the aggregative flow of excitons, and the energy redshift increases linearly with increasing the strain at the outer edge of the Cd Se nanowire. Our results show an effective method to drive, concentrate, and utilize the excitons in Cd Se nanowires, which provides a guide for the design of high performance and flexible optoelectronic nanodevices.
调制Cd Se纳米线的电子结构和发光性质对于进一步开发其在光电子功能器件中的应用具有十分重要的意义.本研究揭示了弯曲Cd Se纳米线中激子流的汇聚效应.弯曲形变在Cd Se纳米线中形成从弯曲内侧到弯曲外侧连续变化的带隙,从而激子在能量梯度诱发的等效内建场的驱动下向较低能量的弯曲外侧漂移和汇聚.由于激子迁移到弯曲外侧边缘并复合发光,使得激子发光光谱在弯曲横截面发生整体红移,并且发光能量的红移量随弯曲外侧边缘的最大拉伸应变线性增加.本文展示了一种新的驱动、汇聚乃至利用Cd Se纳米线激子的有效方法,对于开发和设计高性能的柔性光电子器件具有重要的指导意义.
基金
supported by the Ministry of Science and Technology of China (2013CB932602, 2013CB934600)
the National Natural Science Foundation of China (NSFC) (11274014, 11234001)
the Program for New Century Excellent Talents in University of China (NCET-12-0002)
