EL characteristics of a TFEL/TFT stacked structure display device driven by a HV-Si·TFT circuit

TFEL/TFT stacked structure display devices were fabricated onto a quartz substrate. By using a HV-TFT circuit as the basis of a TFEL/TFT device, an EL device on the TFT circuit can be switched at a sufficiently low signal line voltage of V/sub s/=2-3 V. The maximum brightness of the TFEL/TFT device is 230 cd/m/sup 2/ and the ON/OFF brightness ratio is more than 90 between Vs=0 and Vs=4 V at a V/sub app/ frequency of 5 kHz and a voltage of 50. Evaluation of the dynamic behavior of TFT circuits using multichannel HV-Si/spl middot/TFT's showed that the rise time of the fundamental TFT circuit at the EL driving point of the circuit was about 20 /spl mu/s and that the hold time of the circuit was about 70 mS. The rise time and the fall time of the luminescence were each about 20 /spl mu/s. The memory characteristics of the TFEL/TFT device showed that the hold time of the luminescence was about 40 mS. These dynamic characteristics of the TFEL/TFT stacked structure device satisfy the conditions required for a flat panel display.