Improved optical mura by beam compensation resonator of excimer laser for AMOLED displays

Herein, we report the ultimate low grayscale optical mura in active-matrix organic light-emitting diode displays, which is one of the most important display qualities, via an excimer laser annealing process-based low-temperature polycrystalline silicon for thin-film transistor pixel circuits. This was systematically investigated through a static shot mode, and square-shaped polycrystalline silicon grains were obviously grown at the interface between the flat-top region and steepness of the short axis in the line beam. Additionally, it was found that a new change in the structure of the high reflector and output coupler could decrease the short axis fluctuation of the laser beam, improving the fluctuation of the flat-top region in the short axis line beam, which leads to better optical mura. Firstly, when looking at the shaking of the laser beam, it was confirmed that the diagonal twisted beam profile appeared in one direction of the conventional resonator was compensated in both directions with conversely twisted angle of the beam compensation resonator. Secondly, the entire transferring laser beam symmetry was enhanced as the irregular asymmetric center-peak fluctuation to the left or right side is nearly fixed without shift, and the flat-top slope of line beam was fluctuated with the range of ± 20 in the conventional resonator, but it was stabilized to within ± 10 in the beam compensation resonator. Finally, the sigma value of micro photoconductive response in the 1 cycle of gas lifetime was similar to that in the initial of gas lifetime. The fluctuations were slightly more stable in beam compensation resonator. The fluctuation up to maximum 0.73 was observed in the conventional resonator at the end of gas lifetime, but in the beam compensation resonator, it was drastically reduced to less than maximum 0.30. Consequently, the optical mura was improved by the laser-induced optical mura using the beam compensation resonator compared to the conventional resonator in the mode of W10 extremely viewing low grayscale.