Prior to dip coating, the substrate

Prior to dip coating, the substrates were cleaned thoroughly. The glass substrate was removed from the solution with a velocity of 24 cm/min and the deposited substrate was moved vertically in the furnace which has the size of 120 cm along the moving direction and the temperature gradient was changed from room temperature to the desired level. The as-deposited films were dried at 773 K to remove themixed solvent and to exclude the organic substances. After the drying process, the dried films were