Development of an active-matrix "HEED" cold cathode and its application to an image sensor
For practical advantages of the HEED (high-efficiency electron emission device) such as a low driving voltage, a high emission current density, especially application to an ultra high sensitive compact image sensor can be expected. A prototype active-matrix HEED image sensor integrated with scanning driver circuits was developed with a HARP (high-gain avalanche rushing amorphous photoconductor) target. It was demonstrated that the prototype 256 times 192 pixels active-matrix HEED array operates well as an effective probe for high-resolution image pickup under dim lighting. The possibility of the active-matrix HEED for development of next-generation image sensor with ultra high sensitivity and high definition was concluded in this report
High Efficiency Electron-Emission in Pt/SiOx/Si/Al Structure
A high efficiency electro-emission device (HEED) has been developed with a structure of Pt/SiOx /Si/Al on a thermally-oxidized Si substrate. The thicknesses of the SiOx and Si films were 400 nm and 5 µ m, respectively. Electron emission characteristics of the HEED are reported. It was found that the HEED has an electron-emission efficiency as high as 28% and a high brightness of 80 kcd/m2 using phosphor ZnS:Cu,Al. This high electron-emission efficiency was obtained in a range of applied voltage in which negative resistance occurred.
Growth from Solutions
Growth from solutions is the crystallization of a compound whose chemical composition differs markedly from that of the initial liquid phase. Commonly used solvents are water, multicomponent aqueous or nonaqueous solutions, and melts of some chemical compounds. Differentiations are made based on growth temperatures and on the chemical nature of the solvent. In growth from low-temperature aqueous solutions, the temperatures generally do not exceed 80–90°C; in growth from superheated aqueous solutions (hydrothermal method), they reach 800°C, and in growth from salt melts (molten-salt, flux, or fluxed melt growth), they usually do not exceed 1200–1300°C, but sometimes reach 1500°C.