First Principle Investigation On The Conducting Properties Of Several Organic Semiconductors

Over the past decades, organic semiconductors have attracted immense in-terest due to their potential use as low-cost alternatives to silicon. In this work, the Marcus-Hush hopping theory are used to evaluate the charge transfer mobili-ty values. We investigated the charge transfer mobility values of Oligothiophenes derivatives, Tetracenes derivatives as well as Naphthalenediimide derivatives. The main work are summarized as follows:The maximum electron transfer mobility of 2,5-di(thiophen-2-yl)thieno [3,2-b]thiophene (T-T2-T) can reach 0.226 cm2V-1s-1. The influence of molecular conjunction length on reorganization energy, electronic coupling and charge-transfer mobility values are analyzed.Tetracenes and their derivatives are high mobility materials for the advantages of small reorganization energies and large electronic couplings. The introduction of long alkyl chains had little influence on reorganization energy. Besides, the com-pact packing mode caused by large alkyl chains would facilitate electronic coupling, improving charge transfer mobility values.C8-NDTI, with rigid structure and special element, possess high charge trans-fer mobility values. We give a detailed analysis about the influence of element on reorganization energies through the normal-mode analysis and bond length relax-ation analysis. The calculated results show that the introduction of atom 0 would decrease reorganization energy in hole-hopping process and increase electronic cou-pling.