FREQUENCY CHARACTERISTICS OF MODERN LED PHOSPHOR MATERIALS

• Main Authors: Maxim S. Fudin, Karim D. Mynbaev, Harri Lipsanen, Katerina Е. Aifantis, Vladislav E. Bougrov, Alexei E. Romanov
• Format: Article
• Language: English
• Published: Saint Petersburg National Research University of Information Technologies, Mechanics and Optics (ITMO University) 2014-11-01
• Series: Naučno-tehničeskij Vestnik Informacionnyh Tehnologij, Mehaniki i Optiki
• Subjects: white LEDs; data transfer; optical wavelengths; phosphors; bandwidth
• Online Access: http://ntv.ifmo.ru/file/article/11192.pdf
• ISSN: 2226-1494; 2500-0373

Frequency characteristics of modern LED phosphor materials have been considered for the purpose of assessing the prospects of phosphor-based LEDs in wireless communication data systems which use optical wavelengths. The measurements have been carried out on the dependence of the emission intensity of single LEDs and LED chip-on-board modules with phosphors based on yttrium-aluminum and lutetium-aluminum garnets (with or without addition of nitridebased phosphors) as well as silicate-based phosphors, on the frequency of electric pulses exciting the emission. It was shown that from the point of view of data transmission rate, garnet-based phosphors (including systems with added nitride phosphors) are more promising than silicate–based ones. Garnet-based materials can be used in optical communication data systems with bandwidth (without extra modulation applied) up to 3 MHz with single–chip LEDs and up to 4.5 MHz with 9- chip LED chip-on-board modules. The results of the work indicate that a significant part of white LEDs used in general lighting systems can be even now used for data transfer, for example, in systems assisting positioning in closed spaces to facilitate people searching necessary rooms or objects