Functionalized Benzothiadiazole Non-Fused A-D-A'-D-A Small Molecules for Effective Electron Mobilities and Metal-free Photocatalysis.

Three non-fused A-D-A'-D-A π-conjugated metal-free small molecules BT-IT1, BT-IBT2 and BT2F-IBT3 have been synthesized and their absorption characteristics and redox properties, as well as charge carrier mobilities have been investigated. The resultant molecules exhibited broad absorption in the range of 325-600 nm in solutions and in thin films the absorption range is 350-700 nm. These new conjugated small molecules showed low-lying HOMO energy levels (-5.49 to -5.50 eV), deep LUMO energy levels (-3.67 to -3.69 eV) and narrow bandgaps of (Eg CV ) ∼0.79 eV. Appreciable electron mobilities for compounds BT-IBT2 and BT2F-IBT3 were 4.56×10-3 and 1.12×10-3  cm2 V-1 s-1 , respectively, obtained by space-charge limited current (SCLC) measurements. Additionally, excellent photocatalytic performances of BT-2T (6), BT2F-2T (10), BT-IT1, BT-IBT2 and BT2F-IBT3 for highly selective oxidation of thioanisole to desired sulfoxides under visible light irradiation were observed.

Defective GaAs nanoribbon-based biosensor for lung cancer biomarkers: a DFT study.

Density functional theory-based first-principles investigation is performed on pristine and mono vacancy induced GaAs nanoribbons to detect the presence of three volatile organic compounds (VOCs), aniline, isoprene and o-toluidine, which will aid in sensing lung cancer. The study has shown that pristine nanoribbon senses all three analytes. For the pristine structure, we observe decent adsorbing parameters and the bandgap widens after the adsorption of analytes. However, the introduction of the carrier traps induced by defect causes deep energy wells that vary the electrical properties as indicated in the bandgap analysis of GaAs, wherein adsorption of aniline and o-toluidine reduces the bandgap to 0 eV, making the structure highly conductive in nature. The adsorption energies of defect-induced nanoribbon are more as compared with the pristine counterpart. Nonetheless, the introduction of defects has improved the sensitivity further.

Analysis of uric acid adsorption on armchair silicene nanoribbons: a DFT study.

Density functional theory based first-principles investigation study is done on armchair silicene nanoribbons (ASiNRs) for adsorption of uric acid molecule. Pristine and defect-induced variants of ASiNR are considered, and the electronic and transport properties are calculated with the adsorption. The pristine ASiNR with zero band gap is engineered with defect to create a band gap, and a significant change in the band structure of defective ASiNR after the adsorption is observed. The adsorption energy of the defective complex is calculated as - 9.21 eV which is more compared to that of the pristine counterpart, whose adsorption energy comes out to be 7.76 eV. The study shows that introduction of defect reduced the sensitivity of ASiNR toward uric acid molecule.