Hofmann Clarissa L M, Eriksen Emil H, Fischer Stefan, Richards Bryce S, Balling Peter, Goldschmidt Jan Christoph
Opt Express. 2018 Mar 19;26(6):7537-7554. doi: 10.1364/OE.26.007537.
This paper presents a simulation-based assessment of the potential for improving the upconversion efficiency of β-NaYF:Er by embedding the upconverter in a one-dimensional photonic crystal. The considered family of structures consists of alternating quarter-wave layers of the upconverter material and a spacer material with a higher refractive index. The two photonic effects of the structures, a modified local energy density and a modified local density of optical states, are considered within a rate-equation-modeling framework, which describes the internal dynamics of the upconversion process. Optimal designs are identified, while taking into account production tolerances via Monte Carlo simulations. To determine the maximum upconversion efficiency across all realistically attainable structures, the refractive index of the spacer material is varied within the range of existing materials. Assuming a production tolerance of σ = 1 nm, the optimized structures enable more than 300-fold upconversion photoluminescence enhancements under one sun and upconversion quantum yields exceeding 15% under 30 suns concentration.
本文提出了一种基于模拟的评估方法，通过将上转换材料嵌入一维光子晶体来提高β-NaYF:Er的上转换效率。所考虑的结构族由上转换材料的交替四分之一波长层和具有较高折射率的间隔材料组成。在速率方程建模框架内考虑了这些结构的两种光子效应，即修正的局部能量密度和修正的局部光学态密度，该框架描述了上转换过程的内部动力学。通过蒙特卡罗模拟确定了最优设计，同时考虑了生产公差。为了确定所有实际可实现结构的最大上转换效率，在现有材料范围内改变间隔材料的折射率。假设生产公差为σ = 1 nm，优化后的结构在一个太阳光照下可实现超过300倍的上转换光致发光增强，在30倍太阳聚光下上转换量子产率超过15%。
