A facile blade-coating process is developed for large area deposition of uniform thick organic active layers in organic photodiodes (OPDs). Large-area semi-transparent top metal electrodes are thermally evaporated with an optimal deposition rate to achieve good balance between transparency and conductivity for top illumination integration structure with the organic thin-film transistor (OTFT) backplane. The maximum process temperature of the OPD is 85 ℃, so that the performance of the OTFT underneath is not affected. Based on the developed integration structure and processes, an all-organic integrated flexible active-matrix imager is developed, having the largest size (130 mm × 130 mm), highest resolution (1536 ×1536 pixels, 300 ppi) and lowest process temperature (100 ℃) reported so far for the OPD based imagers.