Semiconductor Performance of Phthalocyaninato Lead Complex and Its Nonperipheral Substituted Derivatives for Organic Field Effect Transistors: Density Functional Theory Calculations

Abstract

Density functional theory (DFT) calculations were carried out to investigate the semiconductor performance for the organic field effect transistor (OFET) of PbPc, PbPc(α-OC2H5)4, and PbPc(α-OC5H11)4 {Pc2− = dianion of phthalocyanine; [Pc(α-OC2H5)4]2− = dianion of 1,8,15,22-tetraethoxyphthalocyanine; [Pc(α-OC5H11)4]2− = dianion of 1,8,15,22-tetrakis(3-pentyloxy)phthalocyanine} in terms of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy, ionization energy (IE), electron affinity (EA), and their reorganization energy (λ) during the charge-transport process. On the basis of Marcus electron transfer theory, transfer integral (t) and field effect transistor (FET) properties for the three compounds with known crystal structure have been calculated. In line with the experimental result that PbPc can also work as an n-type semiconductor in addition to a p-type one, theoretical calculations reveal that PbPc has relatively large electron affinity to ensure effective electron injection from Au electrode. Introducing four ethoxy groups on the nonperipheral positions of PbPc decreases both the hole and electron injection barrier relative to Au electrode, and the hole and electron reorganization energy becomes very balanced, making PbPc(α-OC2H5)4 a better ambipolar semiconductor material than PbPc. However, nonperipheral pentyloxy substitution lifts the energy level of both HOMO and LUMO and thus decreases both the IP and EA value of PbPc, resulting in improved hole injection ability but worsened electron injection process. The transfer mobility for electron is revealed to be as large as 0.39 cm2 V−1 s−1 for PbPc and 0.16 cm2 V−1 s−1 for PbPc(α-OC5H11)4. The present work will be helpful to understand the electronic nature for PbPc to work as ambipolar semiconductor and to rationally design novel semiconductor materials for OFET usage.

Theoretical Investigation on Charge Transfer Properties of 1,3,5-Tripyrrolebenzene (TPB) and its Derivatives with Electron-withdrawing Substituents

“…Considering the facts that the electron Heff of the dimers mainly estimates the interactive strength between the monomer LUMOs and the LUMOs of these monomers mainly located in the benzene rings as shown in Figure 4, we define that all hopping distance for electron (re) are the center of mass of the parallel benzene ring, while hole hopping distance (rh) are the distance between the centers of mass of the two monomers as most works done. [48,55,57,58,59] In Figure 5, re and rh for all dimers were listed (in 9, the adjacent molecular benzene rings is not parallel and have no obvious benzene overlap anymore. Thus the re and rh are neglected).…”

“…In many simulations of single crystals, most hopping pathways have small Heff and these small Heff hardly contribute to the charge mobility. [57,59,60] Thus, we studied the charge transport property by the face to face dimers. In this work, the PW91PW91 functional was used to evaluate the Heff as shown in Table 8.…”

Tuning Semiconductor Performance of Nickel Complexes through Crystal Transformation

“…These results indicate that the change in the bond length of NiL 2 upon either oxidation or reduction is somewhat large in comparison to macrocycle π-conjugated molecules such as phthalocyanines. 27 As a result, the reorganization energy for both hole and electron transfer would be large (vide infra). Nevertheless, the bond length variation upon reduction is larger than that upon oxidation, suggesting a much larger reorganization energy for electrons of NiL 2 in comparison to the reorganization energy for holes.…”

“…For example, the supramolecular interactions and formation of two structural polymorphs from one building unit in a one-pot synthesis were studied with the help of DFT calculations . First-principles theoretical studies can play a pivotal role in semiconductor material design by enabling a fundamental understanding of the inherent charge transfer behavior in organic semiconductor materials, facilitating the determination of the corresponding material properties and establishing connections among molecular/electronic structures of organic semiconductor materials, their properties, and the performance of the electronic/photovoltaic devices based on such organic semiconductor materials. − …”

Toward panchromatic organic functional molecules: Density functional theory study on the nature of the broad UV–Vis–NIR spectra of substituted tetra(azulene)porphyrins

“…In addition, Pople basis sets have been proved excellent for calculating the structure and properties of porphyrins and phthalocyanines as well as their analogs [80][81][82][83], leading to many applications in this field. Both DFT and TDDFT calculations were carried out using the basis set of 6-311++G(d,p).…”