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Dy2O3 and white LEDs

A light emitting diode (LED) is any substance that emits light when a current passes through it  through it. Blue LEDs were quickly followed by yellow LEDs.  While LEDs can be obtained by combining blue and yellow LEDs using the complement color system.   Unfortunately,  glitches in color rendering result in the “white LED” light appearing to be a pastel shade.  While not technically an LED,  Dy2O3  doped glass might offer a solution.

Jaidass and coworkers (2018) doped lithium zinc  borosilicate glass with  different molar amounts of Dy3+ .All components were of high purity:   B2O3, SiO2, Al2O3, LiF, ZnO and Dy2O3 (99.99%).   Molar percentages of   were: 0.1, 0.5, 1, and 2%.  Components were  taken into clean and dry alumina crucible and then heated at 1200 °C for 1 h until molten.  The melts were poured on a preheated brass mold and annealed at 350 °C for 7 hours, and cooled to room temperature.

Dysprosium-DOTA_whiteLED1
A. Challenges of obtaining white LED light by mixing combinations of red, blue, and green. B. UV/Vis absorption of LZBS glass doped with D2O3. C. Photo luminescence of LZBS glass doped with different molar percentages of Dy3+

CIE Chromacity diagrams are a convenient way of  visualizing the relationship between proportions of red, green and blue light and the perceived color.  All three colors are a proportion of total light intensity of 1.0.

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A CIE chromacity diagram with perceived colors. White light is a combination of red, green, and blue. B. Data from Jaidass (2018) for three molar percentages of  Dy3+doped LZBS glass.

The authors concluded that their Dy3+  doped LZBS glass would be good for lasers as well as white light emitters.  They would have to excite a 385 nm long UV light source rather than an electrical current.

Jaidass N,, Krishna Moorthi C, Mohan Babu A, Reddi Babu M.(2018)Luminescence properties of Dy3+ doped lithium zinc borosilicate glasses for photonic applications. Heliyon 4(3):e00555. Free Paper

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