Protective layer(s) in organic image sensors

An organic image sensor, comprising:

• an organic photoelectrical conversion structure configured to convert photons having wavelengths falling within a predetermined range into an electrical signal;
• an upper electrode disposed over the organic photoelectrical conversion structure, wherein the upper electrode is transparent to the photons have wavelengths falling within a predetermined range;
• a first charge-blocking structure arranged between the upper electrode and the organic photoelectrical conversion structure and configured to block a first kind of electric charge;
• and
• a first protective structure disposed between the first charge-blocking structure and the organic photoelectrical conversion structure.

A method of forming an organic image sensor, comprising:

• forming a first electrode layer over a substrate;
• forming an organic photoelectrical conversion structure over the first electrode layer;
• forming a protective structure covering a top surface of the organic photoelectrical conversion structure using an atomic layer deposition process;
• forming a first charge blocking layer configured to block a first type of charge over the protective structure;
• and
• forming a second electrode layer over the first charge blocking layer.