【摘要】 采用紧束缚近似计算方法 ,针对小带隙的聚乙炔 (polyacetylene,(PA) )和大带隙的聚对苯撑 (poly(p phenylene) ,(PPP)组成的三嵌段共聚物 (triblockcopolymer) (PA) x (PPP) n (PA) y 和 (PPP) x (PA) n (PPP) y 性质进行了研究 ,发现它们具有典型的量子阱特征。对均聚物PPP和PA以及三嵌段共聚物的态密度(densityofstates,(DOS) )进行了计算分析 ,发现共聚物的态密度与均聚物的态密度有着显著的区别 ,共聚物的带隙的大小介于大带隙的PPP和小带隙的PA之间 ,在共聚物中与PPP的导带和价带的子带隙以及共聚物的导带底和价带顶中 ,所存在的能态密度只能由PA来提供 ,而在共聚物的价带底和导带顶的能态密度则取决于PPP的态密度。更多还原

【Abstract】 Electronic structure and Density of states (DOS) of PPP hompolymer, PA homopolymer and their triblock copolymers have been studied by using a tight-binding calculation. It was found that the electronic structures of copolymers have typical quantum-well characteristics. The density of states of homopolymers was obviously different from that of triblock copolymers. It was verified that the band gaps of copolymers were intervenient between that of -(PA) y - and -(PPP) x -. -(PA) y - provided the density of states for the subbands gaps of -(PPP) x - and the top of valence band as well as the bottom of conduction band of copolymers, but -(PPP) x - supplied the density of states to bottom of valence band and the top of conduction band of copolymers.更多还原