Solvent-induced surface morphology of polymer honeycomb thin films for power generating solar windows

Here, the role of two different solvents viz. chloroform (CHCl3) and chlorobenzene (CB) for the formation and dissolution of honeycomb-structured conductive polymer poly[2,5-bis [3-N,N-diethylamino)-1-oxapropyl]-1,4-phenylenevinylene] (P1) thin films was demonstrated. Surface morphology of the films was investigated using atomic force microscopy (AFM) and it was confirmed that CB was a suitable solvent to obtain a better honeycomb structure over the CHCl3. Also, the film dissolution studies were carried out by immersing the honeycomb structured polymer films in their respective solvents for the specified interval of time, which show that the rate of film dissolution was prominent in CB than CHCl3. Based on the solvent selection, honeycomb structured blend as well as heterojunction (HJ) films were prepared from P1 and EG-C-60 (1:1 wt/wt). Here, morphological studies clearly confirmed that the EG-C-60 molecules were uniformly present only at the nodes and frames of the honeycomb structured blend film (which avoids the formation of exciton pair recombination of polymer), whereas in case of heterojunction film EG-C-60 molecules were unevenly distributed, this discovery could find use in fully exploiting the potential of various material systems, and open up new opportunities to improve the efficiency of OSCs. (c) 2016 American Institute of Chemical Engineers Environ Prog, 35: 1207-1214, 2016