Enhancing the electrical conductivity of PEDOT:PSS with oxetane-based additives for applications in organic photovoltaics as transparent thin film electrodes
; Santos, L.
Enhancing the electrical conductivity of PEDOT:PSS with oxetane-based additives for applications in organic photovoltaics as transparent thin film electrodes , Proc SciKnowledge International Conference on Green Energy and Environmental Technology GEET-22, Rome, Italy, Vol. , pp. - , July, 2022.
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Photovoltaic devices based on organic semiconductors (OPVs) are among the most attractive emerging energy technologies due to enabling employing low-cost techniques for their fabrication, such as printing deposition methods, since organic semiconductors can be processed in solution, as inks. Moreover, they can be fabricated as semi-transparent modules over mechanically flexible substrates therefore allowing for building integration applications, especially in vertical windows or curved roofs. However, OPV devices still face technological challenges to enter into mass production. One is related with the glass-like transparent electrode, which is typically based on a thin layer of Indium-tin-oxide (ITO) and whose cost has been greatly increasing both due to the scarcity of indium element and to the high-cost fabrication of ITO-covered substrates. Moreover, the mainstream transparent electrodes for the manufacture of displays and most PV devices are based on ITO. Therefore, it is urgent to replace of ITO by lower cost and readily available alternative materials to sustain the electronics industry. Here, we present a new method that significantly increases the conductivity poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) thin films and simultaneously keeps or even improves their transmittance in the visible range . PEDOT:PSS is an intrinsic conducting polymer which is commercially available as an aqueous dispersion and therefore can be deposited by low cost methods, as spin-coating. The method involves oxetane reagents to form polyethers and cross-link PSS chains that consequently weaken the Coulombic attraction between PSS and PEDOT. As a result, more ordered and densely packed conducting PEDOT chains are established, thereby favouring charge transport . Finally, the developed films were tested in OPV devices replacing the ITO electrode.