Thin film transistor integration on glass and plastic substrates in amorphous silicon technology

The authors review amorphous silicon (a-Si:H) thin film transistor (TFT) integration and design considerations, including stability, and present examples of integration for two application areas: active matrix organic light emitting diode (AMOLED) displays and active matrix flat panel imagers (AMFPIs) for medical imaging. Pixel architectures and TFT circuit topologies are described that are amenable for vertically integrated, high aperture ratio or high fill factor pixels. Here, the OLED or detector layers are integrated directly above the TFT circuit layer to provide an active pixel area that is at least 80% of the total pixel area with an aperture ratio or fill factor that remains virtually independent of scaling. The design is based on physically-based compact TFT models, which accurately predict both static and dynamic behaviour