Hole Transfer Materials Research Articles

Effect of Cu2O Content in Electrodeposited CuOx Film on Perovskite Solar Cells

It is well known that the different proportions of CuO and Cu2O in CuOx hole transfer materials have a great influence on the hole transport property as well as the device performances of perovskite solar cells (PSCs). In this paper, we changed the content of Cu2O in the film by controlling the deposition voltage during electrodeposition, and the effects of different contents of Cu2O in the films on the device were investigated for the first time. It was found that the content of Cu2O in the film reached the highest point with the deposition voltage 0.5[Formula: see text]V, such films have the highest transmittance and carrier mobility. After assembling the device, the power conversion efficiency (PCE) of the champion device reached 13.48% under a one-sun AM 1.5[Formula: see text]G (100[Formula: see text]mW/cm[Formula: see text] illumination. Furthermore, the unpackaged device based on CuOx still retained over 75% PCE after being placed in the ambient condition (30–40% humidity, 20–30[Formula: see text] for 500[Formula: see text]h.

New Insight into Sulfurized and Selenized Kesterite–Titania Nanostructures for CdS-free and HTM-free Photovoltaic and Voltage-Modulated Photodetecting Applications

Cu2ZnSnS4 or kesterite and its selenium alloyed counterparts are considered promising for next generation photovoltaic applications due to their excellent optoelectronic properties and earth-abundant, nontoxic composition. In order to alleviate the adverse effects of defects and interfaces on charge separation and transport in current thin film kesterite photovoltaics, new solutions such as the application of an inverted superstrate configuration have been proposed. In this article, sulfurized and selenized kesterite were deposited by solution processing on thin ALD Al2O3 coated TiO2 nanorods to fabricate novel nanostructured devices free of additional buffer layers and hole transfer materials (HTM). The selenized kesterite (CZTSSe) solar cell demonstrated an energy conversion efficiency of 1.85% with high Jsc of ∼20 mA/cm2 while the sulfurized kesterite (CZTS) device showed lower solar cell efficiency but excellent photodetecting properties under reverse bias with adjustable working window from visible-o...

The Applications of Polymers in Solar Cells: A Review.

The emerging dye-sensitized solar cells, perovskite solar cells, and organic solar cells have been regarded as promising photovoltaic technologies. The device structures and components of these solar cells are imperative to the device’s efficiency and stability. Polymers can be used to adjust the device components and structures of these solar cells purposefully, due to their diversified properties. In dye-sensitized solar cells, polymers can be used as flexible substrates, pore- and film-forming agents of photoanode films, platinum-free counter electrodes, and the frameworks of quasi-solid-state electrolytes. In perovskite solar cells, polymers can be used as the additives to adjust the nucleation and crystallization processes in perovskite films. The polymers can also be used as hole transfer materials, electron transfer materials, and interface layer to enhance the carrier separation efficiency and reduce the recombination. In organic solar cells, polymers are often used as donor layers, buffer layers, and other polymer-based micro/nanostructures in binary or ternary devices to influence device performances. The current achievements about the applications of polymers in solar cells are reviewed and analyzed. In addition, the benefits of polymers for solar cells, the challenges for practical application, and possible solutions are also assessed.

Exploring the effect of halogens on semiconducting nature of boron doped molecular precursor graphene nanoribbons at molecular and bulk level

The graphene nanoribbons (GNRs) have been established for device applications in numerous fields due to their superb electro-optical properties. GNRs are used in many nanoscale electronic devices, e.g., solar cells, semiconductors, field effect transistors and nonlinear optics. The isolated molecule precursor of boron doped GNR parent compound 5,10-bis(10-bromoanthracene-9-yl)-5,10-dihydroboranthrene (Br-GNR) and its newly designed derivatives 5,10-bis(10-fluoroanthracene-9-yl)-5,10dihydroboranthrene (F-GNR) and 5,10-bis(10-chloroanthracene-9-yl)-5,10dihydroboranthrene (Cl-GNR) were optimized using density functional theory (DFT) at PBE0/6-311G* level. By replacing the –Br by –F atoms in Br-GNR, the ionization potential (IP) and electron affinity (EA) declined. The hole and electron reorganization energies (λ(h)/λ(e)) of halogenated doped GNRs has been systematically compared with some standard hole and electron transfer materials. The smaller λ(h) values are showing that the studied compounds would be superior hole transfer candidates. The density of states and optical properties at bulk level (including dielectric function, refractive indices, conductivity and loss function) have been probed. The polarizability (γ) amplitudes of F-GNR, Cl-GNR and Br-GNR are 34, 21 and 22 times larger than that of para-nitroaniline at same PBE0/6-311G* level. The calculated non-linear optical (NLO) polarizability amplitudes, optoelectronic and charge transfer properties showed that all the compounds would be good contenders for NLO and semiconductor devices.

DFT Modeling of 4,6-Di(2-furyl)pyrimidine Derivatives As Efficient Charge Transfer Materials

We have modeled multifunctional compounds from 4,6-di(2-furyl)pyrimidine, because 4,6-di(2-furyl)pyrimidine has alternate π-rich and π-poor units. The π-backbone has been elongated along with push–pull strategy to reduce the HOMO–LUMO energy gap and to enhance the intra-molecular charge transfer. All the molecular geometries in ground state have been optimized by using density functional theory (DFT). The time dependent density functional theory (TDDFT) was used to compute the absorption spectra. The frontier molecular orbital (HOMO and LUMO) has been conferred and the charge transfer properties have been discussed on the basis of electron affinities, ionization potentials and reorganization energies. We tuned the optical and electronic properties of 4,6-di(2-furyl)pyrimidine derivatives and it is anticipated that the proposed derivatives might be comparable to the widely used hole and electron transfer materials such as pentacene and (tris(8-hydroxyquinolinato)aluminum). The relationship between structure and property has been thoroughly discussed.

Computational modeling of the photovoltaic activities in EABX3 (EA = ethylammonium, B = Pb, Sn, Ge, X = Cl, Br, I) perovskite solar cells

In this work, the effects of the metal cations and halide anions on the performance of ethylammonium-based perovskite solar cells (PSCs) were investigated. For this purpose, hole transfer material (HTM) and EABX3 (EA = ethylammonium, B = Pb, Sn, Ge, X = Cl, Br, I) perovskite structures were considered from the theoretical viewpoint. Time-dependent density functional theory (TD-DFT) and natural bond orbital (NBO) analysis were applied. The molecular orbitals energy alignment of the materials involved in these PSCs as well as the negative values of Gibbs energies of the electron injection (ΔGinj.) at the EABX3/TiO2 interface and hole transfer (ΔGreg.) at the EABX3/HTM interface show that the studied structures can guarantee the basic photovoltaic processes in this type of solar cells. Based on the results, the coupling constant of EABX3/TiO2 (|VRP|) is the most important parameter that affects the photovoltaic properties of the PSCs and an increase in the size of the halides elevates the electron driving force (eVOC) and decreases |VRP|. A different behavior for the electron transfer rate constant (kinj.) against to the dynamic parameters of eVOC and exciton binding energy (EBE) of the photosensitizers was found. Moreover, the perovskites having a higher electric dipole moment (rk,ḱ) are able to harvest the incident photon and show a stronger dependence of the light harvesting efficiency (LHE) to rk,ḱ. Finally, on the basis of the analyses of LHE and the incident photon to current conversion efficiency (IPCE), EAGeCl3 was proposed as a more efficient compound to be used in the PSCs.

Intramolecular and interfacial dynamics of triarylamine-based hole transport materials.

We present steady-state and time-resolved spectroscopic investigations combined with detailed kinetic modelling for the triarylamine derivatives X60 and PTAA which serve as hole transport materials (HTMs) in perovskite solar cells and represent model compounds for organic electronic materials. Photoexcitation of the spiro-fluorene-xanthene X60 populates its S1 state which decays via intersystem crossing (ISC) as well as fluorescence and internal conversion on a nanosecond time scale. Photoexcitation of the PTAA polymer leads to the formation of singlet excitons which relax and migrate in the time regime from a few to about a hundred picoseconds and decay to the ground state with a lifetime of ca. 900 ps. Both X60 and PTAA exhibit efficient photoinduced electron injection into mesoporous TiO2 thin films forming radical cations with characteristic spectral bands, as confirmed by spectroelectrochemistry in solution. Photoluminescence (PL) experiments performed for the HTMs on methylammonium lead iodide perovskite deposited on mesoporous TiO2 show that small molecular HTMs, such as X60, quench the PL much better than the PTAA polymer. Ultrafast transient absorption experiments on the other hand suggest that the hole transfer at the interface between the perovskite and these HTMs is very fast, regardless of the type of HTM. It is therefore concluded that small molecular HTMs infiltrate much better into mesoporous structures and therefore more efficiently accept holes from the perovskite on such thin film architectures due to the better interfacial contact compared with their polymer-based counterparts.

In Situ Synthesis of CdS/Graphdiyne Heterojunction for Enhanced Photocatalytic Activity of Hydrogen Production.

Hydrogen production through artificial photosynthesis has been regarded as a promising strategy for dealing with energy shortage and environmental problems. In this work, graphdiyne (GD) was first introduced to the visible-light catalytic system for hydrogen production, in which a CdS/GD heterojunction was prepared through a simple in situ growth process by adding Cd(AcO)2 into a dimethyl sulfoxide (DMSO) solution containing GD substrate. The as-prepared CdS/GD heterojunction exhibits much higher performance for photocatalytic hydrogen evolution compared to that of pristine GD and CdS nanoparticles. The photocatalytic performance of CdS/GD heterostructure containing 2.5 wt % of GD (GD2.5) is 2.6 times higher than that of the pristine CdS nanoparticles. The enhanced catalytic performance can be ascribed to the formation of CdS/GD heterojunction, in which the presence of GD can not only stabilize CdS nanoparticles by preventing the agglomeration of CdS nanoparticles but also act as a photogenerated hole transfer material for efficiently separating photogenerated electron-hole pairs in CdS. Accordingly, this work provides the potential of GD-derived materials for solar energy conversion and storage.

Molecular engineering of the organometallic perovskites/HTMs in the PSCs: Photovoltaic behavior and energy conversion

In this work, a quantum chemistry study was performed on the organometallic perovskites/organic hole transfer materials (HTMs) in the perovskite solar cells (PSCs) from the molecular engineering viewpoint. Density functional theory (DFT)/time-dependent DFT (TD-DFT) was applied to investigate the electronic structures/excited state properties of a series of the perovskites, ABX3 (A=CH3NH3, NH4, CH(NH2)2, B˭Ge, Sn, Pb, X=Cl, Br, I). On the basis of the energy level of the perovskites, HTMs and TiO2, all perovskite compounds demonstrate a positive response to the hole/electron injection in the PSCs. A high occupied molecular orbital (HOMO) density of the HTMs, TPB, NPB, TPD, MDA1, MDA2, MDA3, TH101 and V950, are distributed over the whole molecule, homogeneously, which makes the hole transfer more proper. Investigation of the photovoltaic properties of the PSCs shows that they are strongly influenced by the chloride anion. The theoretical trend of the exciton binding energy is according to: F- < NH4- < MA-based perovskites. Considering different analyses show that the rate of the electron injection rate constant and the light harvesting efficiency increase by an increase in the electron driving force and electronic chemical potential. The correlation of the band gaps and the chemical nature of the substitutions in the perovskites shows a collapse by an increase in the cation size. Finally, it is proposed that ASnCl3 and AGeCl3 perovskites are better candidates to be applied in the PSCs as photosensitizers due to an improved incident photon to current efficiency.

DFT and TD–DFT calculations of the electronic structures and photophysical properties of newly designed pyrene-core arylamine derivatives as hole-transporting materials for perovskite solar cells

The electronic structures and photophysical properties of three newly designed pyrene (PY) core arylamine derivatives as hole-transporting materials (HTMs) have been studied by DFT and TD–DFT methods. The modifications made in the arylamine wings of the well-studied and successful HTM PYC compound result in three HTMs designated as HTM1, HTM2, and HTM3. Four of the (methoxyphenyl)amine rings in PYC were replaced by (methoxyphenyl) thiophene (HTM1), (methoxyphenyl) furan (HTM2) and (methoxyphenyl) pyrrole (HTM3). The calculated HOMO and LUMO levels of HTMs 1–3 show proper energy matching and hole-injecting layer, indicating that the hole transports of the HTMs 1–3 compounds are very comparable with that of PYC. The matching of HOMO levels of HTM1 and HTM2 and the LUMO level of HTM3 is even better than that of PYC compound. The FMO analysis elucidated that the PY core acts as an electron withdrawal and contributes mainly to LUMO levels and the arylamine wings act as an electron-donating group and contribute mainly to HOMO levels. HTMs 1–3 show large Stokes shifts based on their absorption and emission spectra. Additionally, the hole reorganization energy is less than that of electrons. Thus, their hole mobility is better than their electron mobility. Furthermore, the ionization potentials, electron affinities, and hardness values were also calculated and compared to evaluate the performance of the newly designed HTMs. The nonlinear optical properties for the newly designed HTMs 1–3 have been investigated as they are correlated with the photoelectric conversion performance. We have also predicted the hole and electron mobility of molecules, and the calculated hole mobility values are better than the electron mobility, so it can be concluded that these materials would be competent hole transfer materials.

Optimization of Experimental Parameters for the Performance of Solid-state Dye-sensitized Solar Cells.

The effects of various sample parameters for solid-state dye sensitized solar cells were studied with carrier dynamics measurements and electrochemical measurements. Although many parameters and processes have been decided based on the experience of researchers, the chemical and physical reasons for the selections have not been clarified. We studied the effect of the generally utilized materials and processing such as the blocking layer, titanium oxide thickness, surface treatment, and the selection of dyes and hole transfer materials. Based on our findings, we were able to rationally optimize the structure of the solid-state dye sensitized solar cells in terms of cell performance or the lifetime of charge carriers.

An effective method of predicting perovskite solar cell lifetime–Case study on planar CH3NH3PbI3 and HC(NH2)2PbI3 perovskite solar cells and hole transfer materials of spiro-OMeTAD and PTAA

As stability of perovskite solar cells remains a significant research topic, it is important to be able to predict the long-term stability of any new kinds of perovskite solar cells when new perovskite absorber materials or transport layers or new cell structures are being demonstrated. This work reports a reliable method of determining degradation rate which is resulted from thermal stress. By incorporating three kinds of accelerated tests, the activation energy for photo-thermally driven degradation processes of perovskites solar cells was determined, which is then used to predict its long-term stability using an Arrhenius equation. In addition, thermal stability of CH3NH3PbI3, HC(NH2)2PbI3, PTAA (poly[bis(4-phenyl)(2,4,6-trimethyl phenyl)amine]) and Spiro-OMeTAD (2,2',7,7'-Tetrakis[N,N-di(4-methoxyphenyl)amino]−9,9'-spirobifluorene) are studied. The thermal stability of a planar HC(NH2)2PbI3/PTAA device is better than a planar HC(NH2)2PbI3/Spiro-OMeTAD device which in turn is better than a planar CH3NH3PbI3/Spiro-OMeTAD device due to better thermal stability of HC(NH2)2PbI3 and PTAA. It is predicted that a planar HC(NH2)2PbI3/PTAA device can have a lifetime of more than 3 years (or 1.5 years) at room temperature if 50% (or 25%) drop in power output can be tolerated. While these lifetimes are specific to perovskite material chosen, preparation method and solar cell design, the lifetime prediction method reported here can be verified experimentally. Therefore, the lifetime calculation method developed in this work is a quick and useful tool for determining the relative stability of a perovskite device especially when comparing the merits of different cell structure designs.

Exploration of 1-Arylmethyl-1,3-diphosphacyclobutane-2,4-diyls as Hole Transfer Materials

This paper describes the p-type semiconductor characteristics of 1-arylmethyl-substituted air-tolerant 1,3-diphosphacyclobutane-2,4-diyls, focusing preliminarily on their hole transfer parameters deduced from their crystal and density functional theory (DFT) structures. 1-(2-Anthrylmethy)-3-t-butyl-2,4-bis(2,4,6-tri-t-butylphenyl)-1,3-diphosphacyclobutane-2,4-diyl functions as a p-type field-effect transistor (FET) with semiconductor parameters comparable to its benzyl-substituted derivative. Thienylmethyl groups induced the FET response, and thus we investigated the utility of the 2-thieno[3,2-b]thiophenemethyl group. Critical parameters, including reorganization energies (λ), hole couplings (V), and hole hopping rates (W) were estimated based on experimental and DFT data. The benzyl and 2-anthrylmethy groups constructed hole transfer pathways comparable to that of acenes, whereas the 2-thieno[3,2-b]thiophenemethyl substituent resulted in the assembly of a unique three-dimensional network. The findings described in this study may lead to the fabrication of superior FET devices based on the chemistry of 1,3-diphosphacyclobutane-2,4-diyl.

Graphdiyne: A Metal-Free Material as Hole Transfer Layer To Fabricate Quantum Dot-Sensitized Photocathodes for Hydrogen Production

Graphdiyne (GDY), a novel large π-conjugated carbon material, for the first time, is introduced as the hole transfer layer into a photoelectrochemical water splitting cell (PEC). Raman and ultraviolet photoelectron spectroscopic studies indicate the existence of relatively strong π-π interactions between GDY and 4-mercaptopyridine surface-functionalized CdSe quantum dots, beneficial to the hole transportation and enhancement of the photocurrent performance. Upon exposure to a Xe lamp, the integrated photocathode produces a current density of nearly -70 μA cm(-2) at a potential of 0 V vs NHE in neutral aqueous solution. Simultaneously, the photocathode evolves H2 with 90 ± 5% faradic efficiency over three times and exhibits good stability within 12 h. All of the results indicate that GDY is a promising hole transfer material to fabricate a PEC device for water splitting by solar energy.

Stable high-performance hybrid perovskite solar cells with ultrathin polythiophene as hole-transporting layer

Ultrathin polythiophene films prepared via electrochemical polymerization is successfully used as the hole-transporting material, substituting conventional HTM-PEDOT:PSS, in planar p-i-n CH3NH3PbI3 perovskite-based solar cells, affording a series of ITO/polythiophene/CH3NH3PbI3/C60/BCP/Ag devices. The ultrathin polythiophene film possesses good transmittance, high conductivity, a smooth surface, high wettability, compatibility with PbI2 DMF solution, and an energy level matching that of the CH3NH3PbI3 perovskite material. A promising power conversion efficiency of about 15.4%, featuring a high fill factor of 0.774, open voltage of 0.99 V, and short-circuit current density of 20.3 mA·cm−2 is obtained. The overall performance of the devices is superior to that of cells using PEDOT:PSS. The differences of solar cells with different hole-transfer materials in charge recombination, charge transport and transfer, and device stability are further investigated and demonstrate that polythiophene is a more effective and promising hole-transporting material. This work provides a simple, prompt, controllable, and economic approach for the preparation of an effective hole-transporting material, which undoubtedly offers an alternative method in the future industrial production of perovskite solar cells.

Effect of donor strength of extended alkyl auxiliary groups on optoelectronic and charge transport properties of novel naphtha[2,1-b:6,5-b']difuran derivatives: simple yet effective strategy.

The present study spotlights the designing of new derivatives of 2,7-bis (4-octylphenyl) naphtho [2,1-b:6,5-b'] difuran (C8-DPNDF) by substituting the alkyl groups (methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl groups) at para position. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) methods are employed to optimize the molecular structures in ground and first excited states, respectively. Several electro-optical properties including hole/electron reorganization energies (λh/λe), electron affinities (EAs), ionization potentials (IPs), molecular electrostatic potentials (MEP), and frontier molecular orbitals (FMOs) have been evaluated. Furthermore their transfer integrals and intrinsic mobilities values have also been calculated. From this study, it is found that hole mobility of octyl containing derivative is raised to 4.69 cm(2) V(-1) s(-1). Moreover with attaching octyl group, hole transfer integral values have also been enhanced in newly designed derivatives. The balanced hole and electron reorganization energies, and improved transfer integrals lead to enhanced mobility in derivatives with octyl group, highlighting them as an efficient hole transfer material. Unlike the other electro-optical properties, the intrinsic hole mobility has increased because of transfer integral values of octyl containing derivative C8-DPNDF due to the dense and close crystal packing of C8-DPNDF. However, photostability of furan-based materials has not changed by increasing length of extended alkyl chain. Thus our present investigation highlights the importance of alkyl auxiliary groups that are often neglected/replaced with simple methyl group to save computation costs. Graphical Abstract The hole and electron reorganization energies of naphtho[2,1-b:6,5-b']difuran derivatives.

Theoretical investigation of the static (hyper)polarizabilities and reorganization energy of 4,5-dicyanoimidazole chromophore and derivatives containing benzene rings and a saturated bridge

Calculations at HF, DFT (CAM-B3LYP) and MP2 level were carried out with a 6-31+G(d,p) basis set to estimate the polarizability α, the first β and second hyperpolarizability γ and reorganization energy λ of 4,5-dicyanoimidazole chromophore 1 and derivatives formed by adding a benzene ring 2, a π bond containing bridge plus a benzene ring (styryl) 3, and a biphenyl 4. Three different donors electron groups D were attached at the para position of the rings or to the chromophore. Our results showed that the 〈α〉, βtotal and 〈γ〉 values increased as D: H<OCH3<N(CH3)2. These properties were enhanced when the intra-molecular charge transference was increased due to the substitution of double bonds by aromatic rings in the bridge or by increasing the donor strength of the D group. The increase in the (hyper)polarizability was accompanied by a decrease in the HOMO–LUMO energy gap in agreement with the Valence-Bond Charge-Transfer and sum-over-states models. The reorganization energy data showed that this parameter for electron (λe) and hole transport (λh) for the substituted chromophore (D: OCH3), molecule 3 (D: H and OCH3) and 4 (D: H) are very close to each other. Then, all them should have good charge transport balance performance. Molecule 2 (D: H) showed the smallest λe and higher λh and can be used as electron transfer material, while molecule 3[D: N(CH3)2] showed a small λh, and can be employed as hole transfer material.

A high performance quasi-solid-state self-powered UV photodetector based on TiO2 nanorod arrays.

Self-powered UV photodetectors based on TiO2 and ZnO nanorod arrays have attracted lots of attention in recent years due to their various advantages. Impressive performances were observed in photochemical cell based UV detectors. However, liquid electrolytes are not ideal for long-term operation and are inconvenient for practical applications. Hence there is an urgent demand for replacing liquid electrolytes with solid-state hole transfer materials. Herein we report a nanostructured quasi-solid-state UV photodetector fabricated using a liquid crystal (LC)-embedded electrolyte with a light-trapping scheme. Vertical rutile TiO2 nanorod arrays grown on fluorine-doped tin oxide conductive glass were used as the active photoanode. A high incident photon-to-current conversion efficiency of 29% at 383 nm and a quick response time of less than 0.03 s were observed. In addition, it was revealed that the quasi-solid-state UV photodetector showed visible-blind, high responsivity, fast time response and good photosensitivity linearity in a wide light intensity range. The LC-embedded electrolyte with a light-trapping scheme enhanced the light absorption and thus improved the photodetecting performance. This self-powered device is a promising candidate for application in high-sensitivity and high-speed UV light photodetectors.

Rational design of donor–π–acceptor n-butyl-1,8-naphthalimide-cored branched molecules as charge transport and luminescent materials for organic light-emitting diodes

Four D–π–A bipolar molecules with n-butyl-1,8-naphthalimide (BNI) fragments as acceptors, acetylenes as π-spacers, and different aromatic groups as donors have been designed to explore their optical, electronic, and charge transport properties as charge transport and luminescent materials for organic light-emitting diodes (OLEDs). The frontier molecular orbitals (FMOs) and local density of states analysis have turned out that the vertical electronic transitions of absorption and emission are characterized as intramolecular charge transfer (ICT). The calculated results show that their optical and electronic properties are affected by the different donors of the bipolar molecules. Our results suggest that D–π–A 1,8-naphthalimide derivatives with donors triphenylamine (1), 1-nitrobenzene (2), anisole (3), and 4-phenylbenzo[c][1,2,5]thiadiazole (4) fragments are expected to be promising luminescent materials. Furthermore, 2–4 are expected to be promising candidates for both electron and hole transport materials as well as potential ambipolar charge transport material, whereas BNI and 1 can serve as hole transfer materials only. We have also predicted the mobility of 4 with better performance in three different space groups. On the basis of investigated results, we proposed a rational way for the design of charge transport and/or luminescent materials simultaneously.

Modeling of efficient charge transfer materials of 4,6-di(thiophen-2-yl)pyrimidine derivatives: Quantum chemical investigations

The 4,6-di(thiophen-2-yl)pyrimidine has alternate pi-rich and pi-poor units. To reduce the HOMO–LUMO energy gap and improve the intra-molecular charge transfer pi-backbone has been elongated along with push–pull strategy. The ground state geometries have been optimized by using density functional theory. The frontier molecular orbitals, i.e., highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbitals (LUMOs) have been conferred. The absorption spectra have been computed by using time dependent density functional theory. On the basis of ionization potentials, electron affinities and reorganization energies charge transfer properties have been discussed. We tuned the electronic, photophysical and charge transfer properties of 4,6-di(thiophen-2-yl)pyrimidine derivatives. It is expected that new designed derivatives might be better/comparable to commonly used hole transfer material (pentacene). The smaller reorganization energies revealing that the electron transfer properties of new designed derivatives might be better/comparable to commonly used electron transfer materials (tris(8-hydroxyquinolinato)aluminum). The structure–property relationship has been discussed.