Synthesis and characterization of poly(p-aminoazobenzene) nanosheet as a new derivative of polyaniline containing azo groups under green chemistry condition and its high efficiency in solar cell

Abstract

• The synthesis of a new derivative of polyaniline containing azo group; poly(p-aminoazobenzene) (PPAAB). • The first report of preparation of nanosheets from PPAAB. • The monitoring the process of trans↔cis photoisomerization of the azobenzene segments by UV–vis spectroscopy. • The first report of the polymer solar cell (PSC) fabrication of PPAAB as FTO/TiO2/PPAAB/Al with a high the PCE (η). • Both preparation of polymer and fabrication of PSC are inexpensive, simple, and under a green condition. In recent years, the isomerization of the N N double bonds in two forms, namely the cis ( Z ) and trans ( E ) isomers, of aromatic azobenzenes have attracted great interest. It occurs readily both photochemically and thermally. Thus, aromatic azobenzenes are excellent candidates as molecular switches to build dynamic molecular devices. In this paper, synthesis of poly( p -aminoazobenzene) ( PPAAB ) 1 1 Poly( p -aminoazobenzene) nanosheets as a new derivative of polyaniline containing azo groups by polymerization of diazoaminobenzene as the monomer was conducted in a new, simple and green condition with %72 yield. This is the first report of in-situ polymerization of p -aminoazobenzene ( PAAB) with nanosheet morphology via one-pot route and without application of any template. The PPAAB was characterized and its properties were investigated. The photoisomerization process of the polymer was observed by UV–vis spectroscopy under irradiation at 380 nm for 2 h. This polymer demonstrated good thermal stability and the conductivity about 3.4 × 10 −4 S cm -1 . The XRD analysis showed that the polymer has a semi-crystalline structure. SEM and TEM images also indicated the same results and demonstrated two-dimensional nanosheet morphology with sheet size ranging from 150 nm to several micrometers and thickness about 90 nm. Furthermore, the polymer solar cell (PSC) of PPAAB as FTO/TiO 2 /PPAAB/Al was fabricated and the power conversion efficiency ( η ) was obtained about 1.5%. The result showed that the PSC is completely efficient with a high η in comparison with similar cells in literature with less fabrication costing, simple structure, and under a green condition.