In this work we have theoretically investigated the optoelectronic properties of a series of acceptor–donor–acceptor type molecules by employing density functional theory formalism.

Defect engineering and hetero-interfacial bending are standard approaches for enhancing carrier separation and increasing visible light absorption in a semiconductor photocatalyst. Here, we demonstrate the evolution of sulfur vacancies (V S ) and the self-assembly of a p−n homojunction through prolonged aqueous washing of SnS 2 nanosheets. The experimental studies have validated increased hydrophilicity, layer thinning, V S generation, and extended photocarrier lifetime in washed SnS 2 nanosheets. Density functional theory has revealed the changes in the local electronic structure of SnS 2 in the presence of structural defects. An electrochemical impedance spectroscopy study has shown that V S actuates the self-assembly of a pseudo-p-type SnS layer over n-type SnS 2 to generate the p−n homojunction. The ptype carrier densities are increased twice as the number of washings is increased from 3 to 10 times. The photocatalytic efficacy of the SnS 2 homojunction is evaluated in the study of the degradation of several water contaminants under white light and monochromatic excitations. The proposed mechanism shows that the built-in electric field at the p−n junction promotes the separation of the photogenerated electrons and holes. Meanwhile, V S traps the electrons and transfers them to the catalytically reactive centers to participate in photocatalysis. Our findings demonstrate that a simple approach that involves prolonged aqueous washing of as-produced SnS 2 promotes the formation of V S and the self-assembly of a p−n homojunction in SnS 2 nanosheets with improved visible light photocatalytic performances.

Here, we have investigated some mixed metal hybrid halide perovskite materials by employing first principle calculation method.

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A series of dyes with the D-$\pi$-A architecture has been designed and studied for dye sensitized solar cells (DSSCs). We have used phenothiazine (PTZ) and coumarin (COU) derivative as the...