Study Of Polymer Solar Cells Based On The Ternary System And The Multiple Layers Doping

In this paper, we made a systematic study on a dual ternary system and the self-assembled sinking phenomenon of a conjugated polymer based on a new typed ITO-free inverted polymer solar cells.It has been found that a very fine nanostructure can be realized by a ternary solvent system. An improvement in energy level alignment is also obtained by doping ICBA into a binary PTB7:PCBM[70] blend, whereby the ternary solute system provides an extra new pathway for charge transfer from PTB7 to the PCBM[70]:ICBA alloy. An encouraging PCE of 7.65 % is achieved from the dual ternary system, which is the highest value ever reported for an ITO-free inverted polymer solar cell with a PEDOT:PSS layer as the top semitransparent electrode – a system which is compatible with low-cost large-area roll-to-roll manufacturing.We also report a facile technique of blending the a conjugated polymer PFN into PTB7:PCBM[70] to simplify the coating process and improve the bulk heterojunction(BHJ) polymer solar cell(PSC) performance. The reason and result of the PFN self-organization via a spontaneous vertical delamination onto the ITO surface were investigated by charge transfer state, optical modelling based on transfer matrix formalism, surface energy measurement, impedance spectra analysis in conjunction with atomic force microscope and scanning electron microscope. Moreover, for ITO-free inverted PSCs with PEDOT:PSS as the incident light top-electrode, decent device performance can also be obtained, demonstrating the remarkable universality through this facile strategy.