We have fabricated organic solar cells using highly conductive poly 3,4-ethylenedioxythiophene: poly styrenesulfonate (PEDOT:PSS), which are modified by adding 5 wt. -% ethylene glycol (EG) as an anode without using transparent conducting oxide (TCO). The conductivity of the modified PEDOT: PSS (PEDOT:PSS-EG) film with ethylene glycol (EG) additive was enhanced by three orders of magnitude. With the modified PEDOT: PSS film, we investigated the transmittance of visible range light at various film thicknesses and device performance levels on ITO-free organic solar cells-based highly conductive polymer anodes. The power conversion efficiency (PCE) was governed by the series resistance, which directly determines a short circuit current density (Jsc).