Integration of near infrared and visible organic photodiodes on a complementary metal-oxide-semiconductor compatible backplane

This paper reports about the integration of polymer-based bulk heterojunction organic photo diodes (OPDs) onto complementary metal-oxide-semiconductor (CMOS) compatible electrode materials. The fabrication and performance of four absorber systems in indium tin oxide-free OPDs for sensing applications have been studied. These are based on the following polymer-fullerene blends: Poly(3-hexylthiophene-2,5-diyl):[6,6]Phenyl C61 Butyric Acid Methyl Ester and Poly(3-hexylthiophene-2,5 diyl):Di[1,4] methanonaphthaleno [1,2:2',3';56,60:2",3"] [5,6]fullerene-C60-Ih, 1',1",4',4"-tetrahydro-, indene-C60 bisadduct to detect light in the visible range and Poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl] thieno[3,4-b]thiophenediyl]]:[6,6]Phenyl C71 Butyric Acid Methyl Ester and Poly[2,1,3-benzothiadiazole-4,7-diyl[4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b'] dithiophene-2,6-diyl]]:[6,6]Phenyl C71 Butyric Acid Methyl Ester to detect a wide range of visible and near infrared. Devices were built in top absorption geometry, where the light passes through a transparent cathode towards the absorption layer. The fraction of absorbed photons in the transparent calcium/silver cathode, the titanium nitride/aluminum anode and in the absorption layer Poly(3-hexylthiophene-2,5-diyl):[6,6]Phenyl C61 Butyric Acid Methyl Ester has been simulated for comparison to the experimental results. We found that the spectral sensitivity of the device mainly depends on the absorption blend layer itself, proving that the OPDs on CMOS profit from the advantageous properties of organic absorbers, covering a very broad spectral absorption.