Electrical simulation of the flicker in poly-Si TFT-LCD pixels for the large-area and high-quality TFT-LCD development and manufacturing

In this paper, we present a new flicker evaluation model through the electrical simulation of the optical flicker phenomena in different kinds of poly-Si TFT-LCD arrays for the development and manufacturing of large-area and high-quality TFT-LCDs. We applied our flicker evaluation model to three different types of TFTs; excimer laser annealed (ELA) poly-Si TFT, silicide mediated crystallization (SMC) poly-Si TFT, and counter-doped lateral body terminal (LBT) poly-Si TFT. We compared the flicker quantitatively for these three different TFT-LCDs on 40 in. UXGA scale. We identified three major factors causing the flicker such as charging time, kickback voltage and leakage current, analyzed their relative contributions to the flicker, and evaluated the values of the flicker in decibel (dB) for the three different TFT-LCD arrays. In addition, we show that the flicker is very sensitive to the low-level (minimum) gate voltage due to the large leakage current of the poly-Si TFT, and the low-level gate voltage should be chosen carefully to minimize the flicker.