Optical properties of three sectors in a zinc-oxide single crystal grown under hydrothermal process

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2011-10, Vol.654 (1), p.314-317
• Main Authors: Sugimura, Shigeaki, Endo, Haruyuki, Kashiwaba, Yasube, Sato, Eiichi
• Format: Article
• Language: English
• Subjects: Chip formation; Decay; Detectors; High-speed radiation sensor; Hydrothermal process; Multipixel photon counter; Sensors; Short decay time; Single crystals; Spectrometers; Wafers; Zinc oxide; Zinc-oxide single crystal
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2011.06.094

We evaluated photoluminescence, radioluminescence, transmittance, and decay time at room temperature at each sector of zinc oxide (ZnO) single crystals grown utilizing the hydrothermal process. The −c-sector wafer, grown on the oxygen face of the c-plane seed crystal, has a short decay time and a high light yield and shows properties different from those of other sectors. We also fabricated a radiation sensor by combining the −c-sector chip cut from a wafer and a multipixel photon counter (MPPC). X-rays were detected using sensor with high sensitivity. At room temperature, typical decay time for the −c sector at the near band edge was 700 ps, and the range of relative light yield was thirty- to forty-times larger than that of the +c sector. Therefore, the properties of the −c-sector wafer at the near band edge will be suitable for high-speed radiation sensors in the near future.