Replacement of ITO for efficient organic polymer solar cells

ITO를 대체한 고효율 유기박막 태양전지

We have fabricated organic photovoltaic cells (OPVs) with highly conductive poly 3,4-ethylenedioxythiophene : poly styrenesulfonate (PEDOT:PSS) layer as an anode without using transparent conducting oxide (TCO), which has been modified by adding some organic solvents like sorbitol (So), dimethyl sulfoxide (DMSO), N-methyl-pyrrolidone (NMP), dimethylformamide (DMF), and ethylene glycol (EG). The conductivity of PEDOT:PSS film modified with each additive was enhanced by three orders of magnitude. According to atomic force microscopy (AFM) study, conductivity enhancement might be related to better connections between the conducting PEDOT chains. TCO-free solar cells with modified PEDOT:PSS layer and the active layer composed of poly(3-hexylthiophene) (P3HT) and phenyl [6,6] C61 butyric acid methyl ester (PCBM) exhibited a comparable device performance to indium tin oxide (ITO) based organic solar cells. The power conversion efficiency (PCE) of the organic solar cells incorporating DMSO, So + DMSO and EG modified PEDOT:PSS layer reached 3.51, 3.64 and 3.77%, respectively, under illumination of AM 1.5 (100mW/$cm^2$).