We report on transparent stand alone C-60 top electrodes for small molecule based organic photovoltaic cells. All device layers (including bottom and top electrode) are thermally evaporated in vacuum, guaranteeing fast, reliable, high-purity and low-cost processing. Employing an organic compound as electrode avoids refractive index mismatch between contact and photo-active layer which results in an increased number of photons reaching the absorber layers. The conductivity of C-60 is improved from 10(-8) S/cm to remarkable 4.97 S/cm by optimized molecular n-type doping. Furthermore, it is shown that high doping concentrations change the absorption behavior of C-60, leading to transmittance values over 70% for wavelengths larger than 600 nm with a weak dependence on layer thickness. Organic solar cells employing such an optimized n-doped C-60 top electrode (thickness 200 nm, doping concentration 16 wt%) exhibit power conversion efficiencies of 1.53%. Electrical device simulations based on a discretized equivalent circuit model reveal an efficient lateral charge transport in n-doped C60 electrodes over a few 100 mu m. In combination with a supporting grid electrode (usually employed for large area photovoltaic applications), n-doped C-60 might replace ITO and fill the lack of transparent conductive top electrodes required for roll-to-roll processed semi-transparent organic devices or devices on opaque substrates. (C) 2013 Elsevier B.V. All rights reserved.