Structural origin of gap states in semicrystalline polymers and the implications for charge transport

Article

关键词: RAY-DIFFRACTION PATTERNS;    FIELD-EFFECT TRANSISTORS;    THIN-FILM TRANSISTORS;    HIGH-MOBILITY;    ORGANIC SEMICONDUCTORS;    CONJUGATED POLYMERS;    CARRIER MOBILITY;    CRYSTALLINE;    DISORDER;    TEXTURE;   

DOI  :  10.1103/PhysRevB.83.121306

来源: SCIE

【 摘 要 】

We quantify the degree of paracrystalline disorder in the pi-pi stacking direction of crystallites of a high performing semicrystalline semiconducting polymer with advanced x-ray line-shape analysis. Using density functional theory calculations to provide input to a simple tight-binding model, we obtain the density of states of a system of pi-pi stacked polymer chains with increasing amounts of paracrystalline disorder. We find that, for an aligned film of PBTTT, the paracrystalline disorder is 7.3%. This type of disorder induces a tail of trap states with a breadth of similar to 100 meV as determined through calculation. This finding agrees with previous device modeling and provides physical justification for the mobility edge model.

【 授权许可】

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