The present invention provides a process for forming a substrate for an organic semiconductor component. The process includes the steps of providing a fullerene network (10), providing a semiconductor solution (12), and applying the semiconductor solution (12) to the fullerene network (10), the viscosity of the semiconductor solution (12) being so adjusted that the semiconductor solution (12) infiltrates the pores of the fullerene network (10) and fills it so that the filled network forms a substrate (2). Further provided is a substrate comprising a fullerene network, composed of pure, unsubstituted fullerenes (10), and a semiconductor solution (12). Additionally provided is an organic semiconductor component, particularly an organic solar cell or an organic photodetector, that contains the inventive substrate.