Add to BibSonomy
Abstract
We report that the rare-earth (RE) ion, Sm-doped ZnO, acts as white light emitting vacuum ultraviolet (VUV) phosphors and possesses an ultrahigh color rendering index (CRI) and color quality scale (CQS). The VUV-excited emission spectra measured from the synchrotron source reveal the emergence of multi-color emission bands in the visible-IR region and substantially depend on the concentration of ${{\rm Sm}^{3 +}}$ ions. A mechanism is proposed to elucidate the origin behind the high-energy bandgap excitation of the host charge carrier and subsequent energy transfer to the ${{\rm Sm}^{3 +}}$ states leading to additional green-yellow-orange emission bands of ${{\rm Sm}^{3 +}}{(^4}{{\rm G}_{5/2}}{\to ^6}{{\rm H}_{\rm J}}\;({\rm J} = {5/2},\;{7/2},\;{\rm and}\;{9/2}))$. High-quality cool white light (correlated color temperature 5600 K) having CIE coordinates (0.33, 0.35) with a CRI as high as 95.89 and a CQS value of 94.49 is achieved for ${{\rm Zn}_{0.985}}{{\rm Sm}_{0.015}}{\rm O}$ under synchrotron VUV radiations. This Letter demonstrates that RE activated ZnO-based phosphors are expected to be a promising candidate in solid state lighting, as well as plasma display devices.
© 2020 Optical Society of America
Full Article | PDF ArticleMore Like This
L. Vijayalakshmi, K. Naveen Kumar, and Pyung Hwang
Opt. Lett. 44(20) 5029-5032 (2019)
Gang Yang, Yongsheng Zhu, Xueguo Li, Jinshu Huang, Xiumei Xu, Xiaoxu Ji, Aihua Wang, Jinbing Cheng, and Gencai Pan
Opt. Lett. 46(24) 6043-6046 (2021)
Tae Wook Kang, Young Ji Park, Gyu Jin Jeong, Byungseo Bae, and Sun Woog Kim
Opt. Lett. 46(13) 3231-3234 (2021)