A series of D–π–A star-shaped molecules with triphenylamine (TPA) as a core, 1,8-naphthalimide (NI) derivatives as end groups, and different π-bridges have been designed to explore their optical, electronic, and charge transport properties as organic solar cell (OSC) materials. The calculation results showed that the star-shaped molecules can lower the material band gap and extend the absorption spectrum towards longer wavelengths. The designed molecules own the longest wavelength of absorption spectra, oscillator strength, and absorption region values. Our results suggest that the designed molecules are expected to be promising candidates for OSC materials. Additionally, the molecules with ethyne, thiophene, benzo[c][1,2,5]thiadiazole (BTA), and 2,3-dihydrothieno[3,4-b][1,4]dioxine (DTD) as π-bridges and 4-pyridne, 4-aniline, and H in NI fragments have better hole- and electron transporting balance and can act as nice ambipolar materials. The values of hole mobility of molecules with ethyne as a π-bridge and NI as an end group for Pna2₁ and P2₁/c are 5.30 × 10⁻³ and 1.27 × 10⁻² cm² V⁻¹ s⁻¹, respectively. On the basis of the investigated results, we suggest that molecules under investigation are suitable donors of [6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM) and its derivatives are acceptors of solar cells.

A series of D–π–A diketopyrrolopyrrole(DPP)-based small molecules were designed for organic light-emitting diode(OLEDs) and organic solar cell(OSCs) applications. Applying the PBE0/6-31G(d,p) method, the ground state geometry and relevant electronic properties were investigated. The first excited singlet state geometry and the absorption and fluorescent spectra were simulated at the TD-PBE0/6-31G(d,p) level. The calculated results revealed that the photophysical properties were affected through the introduction of different end groups. Furthermore, the electronic transitions corresponding to absorption and emission exhibited an intramolecular charge transfer feature. Our results suggest that the designed molecules acted not only as luminescent for OLEDs, but also as donor materials in OSCs. Moreover, they can also be used as potential electron transfer materials for OLEDs and OSCs.

N-doped CNTs embedded with N-doped carbon black anchoring surface-clean Pd NCs exhibit exceptionally improved electrocatalytic behavior towards EOR, due to their unique 3D network architecture and abundant N-containing functional groups.

A series of diindole–diimide based small molecules with different aromatic end groups have been designed and investigated theoretically as donor materials for organic solar cells (OSCs). Their optical, electronic, and charge transport properties have been investigated by density functional theory (DFT) and time-dependent density functional theory (TD-DFT). The calculation results showed that the designed molecules can lower the band gap and extend the absorption spectrum towards longer wavelengths. The optical, electronic, and charge transport properties of the designed molecules are affected by the introduction of different aromatic end groups. We have also predicted the mobility of molecules with benzo[d]thiazole and benzo[c]thiophene end groups. Their hole mobility values are 0.157 and 6.57 × 10⁻² cm² V⁻¹ s⁻¹, respectively. Our results reveal that the designed molecules are promising hole transport materials and donors with intense broad absorption spectra for OSCs.