Anisotropic charge transport properties of chrysene derivatives as organic semiconductor: A computational study

Abstract

AbstractWe used density functional theory to calculate the angular resolution anisotropic charge mobility of the substituted chrysene molecules, viz, 4,10‐diphenoxychrysene (DPC), 4,10‐bis(phenylsulfanyl)chrysene (BPSC), and ethyl 8,9,12‐trimethoxychrysene‐6‐carboxylate (ETCC). The highest occupied molecular orbital–lowest unoccupied molecular orbital gap for DPC, BPSC, and ETCC was calculated to be 3.92, 3.83, and 3.81 eV, respectively, which inferred the compounds to be wide‐band‐gap semiconductors indicating that the compounds should have high stability in atmospheric conditions. The fact is also supported by electronic band‐structure calculation. In addition, higher electron affinity of studied compounds as compared with the bare chrysene molecule imparts enhancement of n‐type character in the compounds. The maximum hole ( ) and electron mobilities ( ) for DPC compound were found to be 0.739 cm2V−1s−1 and 0.319 cm2V−1s−1, respectively, at Φ = 0°. On the other hand, in the case of BPSC crystal, comparatively larger anisotropic electron mobility (0.709 cm2V−1s−1 at Φ = 0° and Φ = 179.90°) than the hole mobility (0.208 cm2V−1s−1 at Φ = 127.19° and Φ = 307.10°) was noted. Similarly, in ETCC, the parallel dimers were found to contribute maximum and of 0.052 and 0.102 cm2V−1s−1, respectively, at Φ = 0°. The substitution of ‐SPh in BPSC and ‐OCH3 and ‐CO2CH2CH3 in ETCC have relatively more impact on band reduction than ‐OPh in DPC, thus facilitating electron transport in BPSC and ETCC.