The invention relates to a method for producing image sensors on the basis of TFA technology including of an amorphous thin-layer system that has been applied on a crystalline ASIC. The inventive method enables the production of image sensors on the basis of TFA technology, which improve the picture quality at low luminous intensity by reducing the dark currents. The photodiodes in the thin-layer material that are configured as pixels are linked with transistor structures in the crystalline ASIC via back electrodes. The transistor structures have particularly low leakage currents due to implantation technology or optimization of the production process.