A process of reacting (SnOx)yZnO(1-y) and a fullerene dopant to produce an electron transport layer. (SnOx)yZnO(1-y) is produced from reacting an organic Zn precursor in the amounts of (1-y); an organic Sn precursor in the amounts of y; and a base in the amount of (1-y) to 1.