Sharp Oxide Semiconductor UV2A Small/Medium LCDs for Smartphones, Tablets


Sharp indicated that in collaboration with Semiconductor Energy Laboratory, it has developed and will commercialize a thin-film transistor using InGaZnO. High energy performance LCD panels will be made possible by downsizing the transistor and by increasing the light transmittance for each pixel.

InGaZnO is an oxide semiconductor that allows for thinner thin film transistors (TFTs). TFTs are not transparent and block light so making them thinner allows more light to pass through from the backlight unit. Another benefit might be higher resolutions: more TFTs can be crammed into the same sized LCD. Sharp will combine oxide TFTs with its Ultraviolet-induced Multi-domain Vertical Alignment (UV2A) technology that improves contrast ratio, aperture ratio, response times, and manufacturing costs, yields, and throughput.

Update: Charles Annis, VP, Manufacturing Research, DisplaySearch:

All leading LCD and AMOLED producers have been working on oxide semiconductor TFTs (typically a-IGZO). IGZO offers the potential of low cost and electron mobilities of 10-30X those of a-Si. Higher electron mobility can be used to reduce device size and increase aperture ratio, enhance electronic device integration on to the glass, increase TFT speed, ultra high definition (UD) displays like 4K × 2K at 240 Hz, and is sufficient to drive AMOLED pixels. It is unclear exactly when Sharp started research on oxide semiconductors for TFT LCD, but in December 2009 Sharp presented a paper at IDW Japan suggesting that it had resolved all major issues inhibiting IGZO FPD mass production.