Research Area

Devices and materials for next-generation broadcasting

Summary

  We are researching the next generation of imaging, recording, and display devices and materials for new broadcast services such as 8K Super Hi-Vision (SHV).
  In our research on imaging devices, we made progress in developing 3D integrated imaging devices, low-voltage multiplier films for solid-state image sensors, and organic image sensors. In our work on 3D integrated imaging devices capable of pixel-parallel signal processing, we reduced the pixel size to 50 μm square by halving the diameter of connection electrodes to 5 μm and modifying the circuit layout. We also developed a circuit for eliminating noise and improved the fabrication process. Our work on low-voltage multiplier films for solid-state image sensors with high sensitivity included reducing the dark current by changing the fabrication process and reducing the noise of signal-reading circuits. In our work on single-chip organic image sensors with an image quality comparable to that of a three-chip camera, we improved the efficiency of organic photoconductive films and prototyped a transparent cell for green having a maximum quantum efficiency of 80%.
  In our research on recording devices, we continued with our work on holographic memory with a large capacity and high data transfer rate for SHV video signals, and on a high-speed magnetic recording device with no moving parts that utilizes the motion of magnetic domains in magnetic nanowires. In holographic memory, we developed a prototype drive that has a recording density of 2.4 Tbit/inch2 and a data transfer rate of 520 Mbps and verified its operation by recording and reproducing compressed SHV video signal. We also began studying multi-value recording to increase the recording density and data transfer rate. In magnetic nanowires, we investigated for suitable magnetic nanowire materials, conducted simulations of magnetic domain formation and driving domain analysis, and widened the bandwidth of our recording and reproduction evaluation system in order to increase the driving speed of magnetic domains. This led to magnetic domain driving in excess of 1 m/s, more than 10 times that of conventional devices.
  In our research on displays, we studied an organic light-emitting diode (OLED) with a longer lifetime and solution-processed devices for large SHV displays for home use. We also developed elemental technologies for a next-generation display with higher image quality and lower power consumption. For an OLED with longer lifetime, we researched a device structure and materials that achieve both high efficiency and long lifetime and developed a red OLED device with an internal quantum efficiency of 100% and a lifetime of beyond 10,000 hours. For solution-processed devices, we developed a technology for increasing the mobility of solution-processed oxide TFTs and a technology for improving the efficiency of quantum-dot light-emitting diodes (QD-LEDs). In our work on displays with higher image quality and lower power consumption, we investigated oxide semiconductor materials suited for high-mobility TFTs. We also prototyped driving equipment that controls the temporal aperture in line units to suppress motion blur on hold-type displays such as OLED displays and demonstrated its effectiveness.