Novel AC bias compensation scheme in hydrogenated amorphous silicon TFT for AMOLED Displays

  • Parikh, Kunjal (Samsung Electronics Co., LCD R&D Center, LCD Business) ;
  • Chung, Kyu-Ha (Samsung Electronics Co., LCD R&D Center, LCD Business) ;
  • Choi, Beom-Rak (Samsung Electronics Co., LCD R&D Center, LCD Business) ;
  • Goh, Joon-Chul (Samsung Electronics Co., LCD R&D Center, LCD Business) ;
  • Huh, Jong-Moo (Samsung Electronics Co., LCD R&D Center, LCD Business) ;
  • Song, Young-Rok (Samsung Electronics Co., LCD R&D Center, LCD Business) ;
  • Kim, Nam-Deog (Samsung Electronics Co., LCD R&D Center, LCD Business) ;
  • Choi, Joon-Hoo (Samsung Electronics Co., LCD R&D Center, LCD Business)
  • Published : 2006.08.22

Abstract

Here we describe a novel driving scheme in the form of negative AC bias stress (NAC) to compensate shift in the threshold voltage for hydrogenated amorphous silicon (${\alpha}$-Si:H) thin film transistor (TFT) for AMOLED applications. This scheme preserves the threshold voltage shift of ${\alpha}$-Si:H TFT for infinitely long duration of time(>30,000 hours) and thereby overall performance, without using any additional TFTs for compensation. We briefly describe about the possible driving schemes in order to implement for real time AMOLED applications. We attribute most of the results based on concept of plugging holes and electrons across the interface of the gate insulator in a controlled manner.