White light‐emitting diodes (WLEDs) for road lighting are required to have both the high scotopic to photopic ratio (S/P) and color rendering index (CRI). However, there is a trade‐off between S/P and CRI, and WLEDs commonly having the S/P of 1.68‐2.38 usually exhibit a low CRI. In this work, to provide a best solution to the trade‐off problem we proposed an optimal spectral model for the phosphor‐converted WLEDs (pc‐WLEDs) aiming to figure out the optimal phosphor combination. The Monte Carlo Algorithms combined with the Genetic Algorithm were adopted to obtain the optimization of CRI and S/P by varying the spectral power distributions of WLEDs through adjusting the spectral parameters. Considering the spectral requirements of pc‐WLEDs based on the mesopic vision, we chose CaAlSiN₃:Eu²⁺ and Y₃(Ga,Al)₅O₁₂:Ce³⁺ as the red‐ and green‐emitting phosphors to prepare WLEDs with both high S/P and CRI, respectively. The simulation based on the optimal spectral model led to an optimal pc‐WLED with a high S/P of 2.0‐2.14, Ra > 80 and correlated color temperature (CCT) of 4000‐5000 K, which matches very well with the experimental results of S/P = 2.064, Ra = 93.9, and CCT = 4981 K for the two‐phosphor converted WLEDs. It implies that the optimal spectral model would be used effectively for the spectral design and phosphor selection for WLEDs.

中文翻译：

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中视视觉中使用的磷光体转换的白光发光二极管的最佳光谱模型

要求用于道路照明的白光发光二极管（WLED）具有高的暗视与明视比（S / P）和显色指数（CRI）。但是，在S / P和CRI之间需要权衡取舍，通常S / P为1.68-2.38的WLED通常显示出较低的CRI。在这项工作中，为了为折衷问题提供最佳解决方案，我们提出了一种用于磷光转换的WLED（pc-WLED）的最佳光谱模型，旨在找出最佳的磷光体组合。采用蒙特卡洛算法和遗传算法相结合的方法，对CRI和S / P进行了优化。通过调整光谱参数来改变WLED的光谱功率分布。考虑到基于介观视觉的pc‐WLED的光谱要求，我们选择CaAlSiN ₃：Eu ²⁺和Y ₃（Ga，Al）₅ O ₁₂：Ce ³⁺作为发红光和发绿光的磷光体，以制备具有以下特征的WLED高S / P和CRI。基于最佳光谱模型的仿真导致了最佳pc-WLED，其S / P为2.0-2.14，Ra> 80，相关色温（CCT）为4000-5000 K，与实验结果非常吻合的S / P对于两基色转换的WLED，其= 2.064，Ra = 93.9和CCT = 4981 K. 这意味着最佳光谱模型将有效地用于WLED的光谱设计和荧光粉选择。