TY - JOUR
T1 - Synthesis and upconversion luminescence properties of NaYF4:Yb3+/Er3+ microspheres
AU - WANG, Guofeng
AU - QIN, Weiping
AU - WANG, Lili
AU - WEI, Guodong
AU - ZHU, Peifen
AU - ZHANG, Daisheng
AU - DING, Fuheng
N1 - Funding Information:
Foundation item: Project supported by the National Natural Science Foundation of China (10474096 and 50672030)
PY - 2009/6
Y1 - 2009/6
N2 - Cubic NaYF4:Yb3+(20%)/Er3+(1%) microspheres were synthesized by EDTA-assisted hydrothermal method. Under 980 nm excitation, ultraviolet (4G11/2→4I15/2), violet (2H9/2→4I15/2), green (4F7/2→4I15/2, 2H11/2→4I15/2, and 4S3/2→4I15/2), and red (4F9/2→4I15/2) upconversion fluorescence were observed. The number of laser photons absorbed in one upconversion excitation process, n, was determined to be 3.89, 1.61, 2.55, and 1.09 for the ultraviolet, violet, green, and red emissions, respectively. Obviously, n=3.89 indicated that a four-photon process was involved in populating the 4G11/2 state, and n=2.55 indicated that a three-photon process was involved in populating the 4F7/2/2H11/2/4S3/2 levels. For the violet and red emissions, the population of the states 2H9/2 and 4F9/2 separately came from three-photon and two-photon processes. The decrease of n was well explained by the mechanism of competition between linear decay and upconversion processes for the depletion of the intermediate excited states.
AB - Cubic NaYF4:Yb3+(20%)/Er3+(1%) microspheres were synthesized by EDTA-assisted hydrothermal method. Under 980 nm excitation, ultraviolet (4G11/2→4I15/2), violet (2H9/2→4I15/2), green (4F7/2→4I15/2, 2H11/2→4I15/2, and 4S3/2→4I15/2), and red (4F9/2→4I15/2) upconversion fluorescence were observed. The number of laser photons absorbed in one upconversion excitation process, n, was determined to be 3.89, 1.61, 2.55, and 1.09 for the ultraviolet, violet, green, and red emissions, respectively. Obviously, n=3.89 indicated that a four-photon process was involved in populating the 4G11/2 state, and n=2.55 indicated that a three-photon process was involved in populating the 4F7/2/2H11/2/4S3/2 levels. For the violet and red emissions, the population of the states 2H9/2 and 4F9/2 separately came from three-photon and two-photon processes. The decrease of n was well explained by the mechanism of competition between linear decay and upconversion processes for the depletion of the intermediate excited states.
KW - NaYF:Yb/Er
KW - hydrothermal method
KW - rare earths
KW - upconversion luminescence
UR - http://www.scopus.com/inward/record.url?scp=67649560033&partnerID=8YFLogxK
U2 - 10.1016/S1002-0721(08)60258-6
DO - 10.1016/S1002-0721(08)60258-6
M3 - Article
AN - SCOPUS:67649560033
SN - 1002-0721
VL - 27
SP - 394
EP - 397
JO - Journal of Rare Earths
JF - Journal of Rare Earths
IS - 3
ER -