We report a robust methodology for synthesizing monodisperse alloyed Bi 2 S 3−x Se x nanorods (NRs) to tune optical properties with the variation of Se concentration. The intercalation of Cu(I) into the presynthetic Bi 2 S 3−x Se x NRs converted to ternary Cu 3 BiS 3−x Se x NRs via cation exchange process. The transformation was monitored through the formation of core/shell Bi 2 S 3−x Se x / Cu 3 BiS 3−x Se x nanorod heterostructures. Shape anisotropy results in near-infrared bimodal localized surface plasmon resonance (LSPR) in Cu 3 BiS 3−x Se x nanorod over a broad range from 600 to 3500 nm with increase of Se:S ratio. The LSPR sensitivity, defined as the change in the LSPR peak wavelength per unit change in the refractive index (RI) of the medium, was estimated to be 250−350 nm/RI unit, much higher than other copper chalcogenides like Cu 2 S/Cu 2 Se. A fast photodetector was fabricated by Cu 3 BiS 3−x Se x NRs with high photocurrent gain value (∼125) with Se alloying. The intrinsic Cu vacancies and the effective mass of charge carriers play important roles to manipulate optical and electrical properties of Cu 3 BiS 3−x Se x NRs.

Nanotubular polyaniline/N,N-di((S)-1-carboxylethyl)-3,4 : 9,10 perylenetetracarboxyldiimide hybrids with characteristics of H-type aggregates and secondary de-doping yield photocurrent with photoconversion efficiency of 2.88%.

In order to tune the band positions of the hole-transporting material (HTM) in an interfacially engineered perovskite solar cell (PSC), random copolymers of poly(3-thiopheneacetic acid) and poly(3-hexylthiophene) (P3TAA-co-P3HT) with different compositions were produced by oxidative polymerization. The copolymers were characterized using 1H NMR, FTIR, and UV-vis spectroscopy and gel permeation chromatography. Here, ZnO nanoparticles were used as the electron-transporting material (ETM) and methylammonium lead iodide (MAPbI3) perovskite was used as the light-absorbing material to form an FTO/ZnO/MAPbI3/copolymer/Ag device, of which the power conversion efficiency (PCE) was found to be dependent on the copolymer composition and reached a maximum (∼10%) at a P3TAA content of 43 mol% in the copolymer (P3). The band gaps of the copolymers as determined from UV-vis spectroscopy and cyclic voltammetry exhibit a staggered-gap hetero-interface configuration in which the HOMO and LUMO of P3 closely match those of MAPbI3 and give rise to the maximum PCE. Time-resolved photoluminescence spectra of MAPbI3/HTM samples indicate that charge transfer across the perovskite/copolymer interface was faster with a reduced recombination rate for a P3 sample. The electrochemical impedance spectra (EIS) of the PSCs exhibit Nyquist plots with two semicircles, which correspond to an equivalent circuit consisting of two parallel R-C and R-CPE circuits connected in series. Analysis of the data indicates that the effective electron lifetime was longest for the P3 copolymer, which indicates that the charge recombination was lower than that in the components and other copolymers. The copolymers exhibited an intermediate stability with respect to their components, and amongst the copolymers P3 exhibited the highest stability.

Dye sensitized organic solar cells based on citric acid doped PANI–perylenetetracarboxyldiimide exhibit a moderate efficiency of 4.32%.

Perylene derivatives exhibit good optoelectronic properties and in order to augment it, the self‐assembly of phenyl alanine conjugated with perylene bisimide (PBI) would be a good motif because of excellent self‐organizing power of both the components. So we have synthesized N, N’‐di((S)‐1‐carboxylphenylalanine)‐3,4:9,10‐ perylenetetracarboxyl bisimide (PPA) and have studied its self‐organization in different organic solvents. Microscopic images reveal the formation of vesicles cast from chloroform. There is a gradual change in color from green to yellow to orange to red under UV light with increasing PPA concentration. The emission maximum for the lowest energy peak gradually increases with increase in PPA concentration and the emission intensity shows a maximum at a 4–8 mM concentration due to variation of self‐aggregation nature. Fluorescence of PPA in other solvents also varies in a similar fashion indicating dynamic nature of the self‐assembly with concentration. The current voltage (I−V) property of the dried ensemble from chloroform exhibit negative differential resistance with rectification property indicating co‐existence of holes and electrons. On application of electric field the holes and electrons of the system become recombined generating luminescence, which peak position and intensity vary with increasing applied voltage.