38.2: 302-ppi High-Resolution AMOLED using Laser-Induced Thermal Imaging

Abstract

Samsung SDI has developed 2.6-inch full color VGA Active Matrix Organic Light-Emitting Diode (AMOLED) display with the world's highest resolution of 302ppi using Laser Induced Thermal Imaging (LITI) method with the top emission structure. A voltage compensating pixel circuit with 2μm design-rule in low-temperature poly-Si (LTPS) thin film transistors (TFTs) was introduced to compensate the variation of the threshold voltage (Vth) in order to improve the image quality. Moreover, an aperture ratio of ∼40% was obtained for each pixel even though the sub-pixel pitch was 28um. The luminance for the white color was 200cd/m2 and color gamut was 74% compared to national television standard committee (NTSC) standards. These results show the possibility of high-resolution AMOLED display incorporating the LTPS technology and LITI method for digital mobile era applications in the near future.