Nitta Mitsuru, Nagao Nobuaki, Nomura Yuki, Hirasawa Taku, Sakai Yuki, Ogata Takahiro, Azuma Masaki, Torii Shuki, Ishigaki Toru, Inada Yasuhisa
Technology Division, Panasonic Corporation, 1006 Kadoma, Kadoma, Osaka 571-8508, Japan.
Engineering Division, Life Solutions Company, Panasonic Corporation, 1006 Kadoma, Kadoma, Osaka 571-8501, Japan.
ACS Appl Mater Interfaces. 2020 Jul 15;12(28):31652-31658. doi: 10.1021/acsami.0c09342. Epub 2020 Jul 6.
A novel high-brightness red-emitting phosphor, La(Si,Al)(O,N):Ce (LSA), which can potentially be used as a laser-excited light source, is demonstrated. Laser-excited phosphor system has great potential for use as a white-light source, as it is orders of magnitude brighter than white LEDs. Although conventional yellow-green phosphors show excellent luminescent properties even under high-power laser excitation, red-emitting phosphors, which are essential to achieve a high color-rendering index and low color-temperature, show quantum efficiency quenching. This limits the output power in multiphosphor excitation systems. Ce should successfully tolerate high-power excitation due to the shortest emission lifetime seen in rare-earth ions, caused by the 5d-4f spin-allowed transition; however, a red-emitting Ce-doped phosphor of practical use has not been realized. LSA is described by the crystal-field modification of a yellow-emitting phosphor, LaSiN:Ce, with substitution of Al in Si sites. LSA shows 640 nm red emission together with tolerance for high-power excitation and thermal quenching, suggesting its significant potential for industrial applications that require ultrahigh brightness.
