摘要
We explore Nd3＋ concentration and excitation power dependences of the avalanche upconversion of NdxY1-xVO4 （x=0-1） nanocrystals with uniform size and shape. The avalanche threshold power caused by the near-resonant energy transfer between 4F5/2→4I13/2 and 4F5/2→2G9/2 significantly decreases as the Nd3＋ concentration increases. The off-resonant energy transfer between 4F5/2→4I13/2 and 4F5/2→4G11/2 in the strong excitation regime leads to apparent broadening on the blue-side of the upconversion spectrum of NdVO4 nanocrystals.
We explore Nd3＋ concentration and excitation power dependences of the avalanche upconversion of NdxY1-xVO4 （x=0-1） nanocrystals with uniform size and shape. The avalanche threshold power caused by the near-resonant energy transfer between 4F5/2→4I13/2 and 4F5/2→2G9/2 significantly decreases as the Nd3＋ concentration increases. The off-resonant energy transfer between 4F5/2→4I13/2 and 4F5/2→4G11/2 in the strong excitation regime leads to apparent broadening on the blue-side of the upconversion spectrum of NdVO4 nanocrystals.
基金
Supported by the National Natural Science Foundation of China under Grant Nos 10534030 and 10874134, the National Basic Research Program of China under Grant No 2007CB935304, the Key Project of Ministry of Education under Grant No 708063, and the Research Grants Council of Hong Kong （GRF No 604206）.
