University of Khartoum

Theoretical Design of Functionalization of Organic Semiconductor Materials

Theoretical Design of Functionalization of Organic Semiconductor Materials

Show full item record

Title: Theoretical Design of Functionalization of Organic Semiconductor Materials
Author: Oshi, Rowa Twfig Mohamed
Abstract: In this study, B3LYP density functional theory (DFT) calculations were carried through on organic semiconductor species based on naphthalene (NAPH), anthracene (ANTH), tetracene (TETRA), 7,7,8,8-Tetracyanoquinodimethane (TCNQ), 1,4,5,8-Naphthalenetetracarboxylic dianhydride (NTCDA), and Perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA). In particular, the effects of functionalization by electron with-drawing groups (F, Cl, NO2, CN, and N), and electron donating groups (CH3, OCH3, and OH) on the structure, charge transport, and electronic properties of these specieshave been studied. Special attention is paid to the reorganization energy of the charge transport process, as well as the adiabatic electron affinities (EA), the 1st ionization potential (IP), and the HOMO-LUMO energy gap. According to the calculations, functionalizing by F, Cl, NO2, N, CH3, OCH3, and OH increases the reorganization energies (λ+ and λ-) compared to those of CN-functionalized systems, which can be attributed to the additional contributions of C–R bonds(R=F, Cl, NO2, N, CH3, OCH3, and OH). On the other hand, the functionalization of naphthalene, anthracene and tetracene by electron with-drawing groups leads to an enhancement of the adiabatic electron affinities (EA) and the 1st ionization potential (IP), in contrast to the functionalization of TCNQ, NTCDA, and PTCDA by electron donating groups due to resonance (M) and inductive effects (I) are both taken into account. The HOMO-LUMO energy gaps have been also reported. Species with lower HOMO-LUMO gap such as F, Cl, NO2,CN,N, OCH3, and OH functionalized systems are expected to have higher carrier mobility and lower kinetic stability. In contrast to that of CH3-functionalized systems. From the λ, EA, IP and HOMO-LUMO gap values the Cl-functionalized are predicted to be good n-type systems, whereas CH3- functionalized systems are good p-type candidates.
URI: http://khartoumspace.uofk.edu/123456789/26623


Files in this item

Files Size Format View

This item appears in the following Collection(s)

Show full item record

Share

Search DSpace


Browse

My Account