中国物理B ›› 2009, Vol. 18 ›› Issue (7): 2961-2966.doi: 10.1088/1674-1056/18/7/057
李元1, 尹笋1, 刘德胜1, 高琨2, 解士杰2, 赵显3
Gao Kun(高琨)a)b)† , Xie Shi-Jie(解士杰)a)b), Li Yuan(李元)a), Yin Sun(尹笋)a), Liu De-Sheng(刘德胜)a), and Zhao Xian(赵显)b)
摘要: The effect of interchain coupling on the formation and the stability of a biexciton is studied in poly (p-phenylene vinylene) chains in the framework of the tight-binding approach. We obtain an intrachain exciton and biexciton as well as an interchain exciton and biexciton through a double-photon excitation. It is found that a biexciton is energetically favourable to two single excitons even when there exists an interchain coupling. There is a turnover value t⊥C of the interchain coupling for the formation of a biexciton, beyond which two excitons are combined into one biexciton. The binding energy of a biexciton is calculated to decrease with the increase of interchain coupling, which indicates that a biexciton is relatively stable in polymers with a weak interchain coupling. The conclusion is consistent with the experimental observations. In addition, a suggestion about how to improve the yielding efficiency or the formation of biexcitons in actual applications is given.
中图分类号: (Excitons and related phenomena)