Publications

Non-fullerene (NF)-based compounds have attracted much attention as compared to fullerene-based materials because of their promising optoelectronic properties, lower synthetic cost and greater stability. Usually, the end-capped groups have a promising impact in magnifying the nonlinear optical (NLO) characteristics in the non-fullerene molecules. Based on this, a series of new NLO active non-fullerene molecules (NFAD2-NFAD6) have been established. The non-fullerene molecules (NFAD2-NFAD6) were designed by end-capped modification in acceptor moieties of the reference (NFAR1), while donor and π-bridge moieties were kept the same in the entire series. Quantum chemistry-based calculations at the M06/6-311G(d,p) level were done to determine the NLO characteristics and for other supportive analyses. The acceptor and donor moieties were utilized at the opposite terminals of NFAD2-NFAD6, which proved to be an effective approach in tuning the FMO band gap. Overall the results of natural bond orbital (NBO), density of state (DOS) and transition density matrices (TDMs) analyses supported the NLO properties of the designed compounds. Among all the studied compounds, NFAD4 was proven to be the most suitable candidate due to its promising NLO properties, well supported by a lower bandgap of 1.519 eV and a maximum absorption wavelength of 999.550 nm. Therefore, NFAD4 was reported with greater amplitude of dipole polarizability (10.429 e.s.u), average polarizability (2.953 × 10^-22 e.s.u), first hyperpolarizability (13.16 × 10^-27 e.s.u.) and second hyperpolarizability (2.150 × 10^-31 e.s.u.) than other derivatives and NFAR1. Subsequently, the present study depicted the significance of utilizing different non-fullerene (NF)-based acceptor moieties to achieve the promising NLO material. This computational study may lead towards new plausible pathways for researchers to design potent NLO substances for impending hi-tech applications.

A new class of phenanthrene-fused BF₂ azadipyrromethene (azaBODIPY) dyes have been synthesized through a tandem Suzuki reaction and oxidative ring-fusion reaction, or a palladium-catalyzed intramolecular C-H activation reaction. These phenanthrene-fused azaBODIPY dyes are highly photostable and display markedly redshifted absorption (up to λ=771 nm) and emission bands (λ≈800 nm) in the near-infrared region. DFT calculations and cyclic voltammetry studies indicate that, upon annulation, more pronounced stabilization of the LUMO is the origin of the bathochromic shift of the absorption and high photostability.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

As a promising candidate for photoelectrochemical (PEC) water oxidation, the photoelectrochemical water splitting efficiency of hematite (Fe2O3) is limited by its low electron mobility. In this work, we report a new strategy for great enhancement of PEC water oxidation activity on Fe2O3. The S-doped Fe2O3 (S:Fe2O3) nanorods array on a Ti plate shows a substantially increased photocurrent density of 1.42 mA cm–2 at 1.23 V vs RHE in 1.0 M NaOH under simulated sunlight irradiation (AM 1.5G, 100 mW cm–2), 2.45 times that of Fe2O3 counterpart (0.58 mA cm–2). Both density functional theory calculations and experimental measurements verify that the superior activity is contributed to the enhanced electron mobility after S doping. This study offers an attractive photoanode in water-splitting devices for solar hydrogen production application.

Two structural isomers of carbazole decorated with triarylamine have been designed and synthesized with a facile synthetic procedure. The impact of triarylamine substitution on the isomeric structural linkage of carbazole on the optical, thermal, electrochemical, and photovoltaic properties has been extensively studied by combining experimental and simulation methods. Car[2,3] showed a red shift in the absorption maximum compared to that of Car[1,3], indicating the linear conjugation along the 2,7-position of carbazole in the former. The high thermal decomposition temperature (>420 °C) of these compounds could be attributed to the rigid structure of the carbazole core. Perovskite solar cells fabricated with Car[2,3] as the hole transporting material (HTM) displayed the highest power conversion efficiency (PCE) of 19.23%. It can be attributed to the suitable energy alignment of the highest occupied molecular orbital (HOMO) of HTM with the adjacent perovskite valence band energy level, which results in efficient hole transport. Furthermore, the molecular dynamic simulation demonstrates that the triphenylamine substitution on the 2,3,6,7 positions of Car[2,3] results in a more planar molecular alignment on top of the perovskite surface, promoting an efficient hole extraction. Essentially, when Car[1,3] and Car[2,3] were applied in perovskite solar cells, they showed enhanced long-term stability by retaining >80% of their initial PCEs after 1000 h of continuous illumination.