Nanocomposite solar cells the requirement and challenge of kinetic charge separation

Nano crystalline solar cells promise significant advantages with respect to cost efficient mass production since they do not require imprinted chemical potential gradients for charge separation e.g. electrical fields generated by p, n doping, which should last for 1 3 decades . They, however, require kinetic charge separation, chemical electronic mechanisms which rectify photocurrents for energy conversion. Such mechanisms are presently not well understood, since the existing nano solar cells dye and polymer solar cells have evolved largely empirically. It is shown here that function and properties of kinetically determined solar cells can be derived from irreversible thermodynamic principles considering minimum entropy production or the principle of least action and involve solid state electrochemical processes. On the basis of this model presently studied nano solar cells and also the primary photosynthetic mechanism are analyzed to identify the most significant physical chemical factors involve