A TFA (thin film on ASIC) image sensor with stability-optimized photodiode for converting electromagnetic radiation into an intensity-dependent photocurrent. The TFA includes an intermetal dielectric layer, pixel back electrodes, vias, metal contacts, a transparent conductive oxide (TCO) layer, and an intrinsic absorption layer with a thickness between 300 nm and 600 nm. The pixel back electrodes are disposed over the intermetal dielectric layer, which is disposed over the ASIC. The vias connect to the pixel back electrodes and the metal contacts, which are formed in the intermetal dielectric layer. The TCO is disposed above the intrinsic absorption layer, which is disposed above the pixel back electrodes.