Prospects of colour selective organic photodiodes†
Currently, image sensors are in the limelight as a key technology solution for various light detection applications such as smart phones, self-driving vehicles, drones and machine vision, etc. In particular, organic semiconductors are attracting attention as a newly emerging material for image sensor applications requiring a tuneable absorption spectrum, owing to their relatively higher absorption coefficient compared with inorganic semiconductors. Considering that colour filters generally used in the conventional Si-based image sensor architecture exhibit various limitations, there have been intensive research efforts to replace Si-based photodiodes with colour selective organic photodiodes (OPDs). In this paper, we have reviewed the recently reported colour selective OPDs according to their specific colour selection methods. Furthermore, we considered each method in detail with regard to its fundamental principles of operation.