To achieve high quality lighting and visible light communication (VLC) simultaneously, GaN based white light emitting diodes (WLEDs) oriented for lighting in VLC has attracted great interest. However, the overall bandwidth of conventional phosphor converted WLEDs is limited by the long lifetime of phosphor, the slow Stokes transfer process, the resistance-capacitance (RC) time delay, and the quantum-confined Stark effect (QCSE). Here by adopting a self-assembled InGaN quantum dots (QDs) structure, we have fabricated phosphor-free single chip WLEDs with tunable correlated color temperature (CCT, from 1600 K to 6000 K), a broadband spectrum, a moderate color rendering index (CRI) of 75, and a significantly improved modulation bandwidth (maximum of 150 MHz) at a low current density of 72 A/cm2. The broadband spectrum and high modulation bandwidth are ascribed to the capture of carriers by different localized states of InGaN QDs with alleviative QCSE as compared to the traditional InGaN/GaN quantum well (QW) structures. We believe the approach reported in this work will find its potential application in GaN WLEDs and advance the development of semiconductor lighting-communication integration.

中文翻译：

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无磷单片GaN基白光发光二极管，显色指数适中，通信带宽显着增强

为了同时实现高质量照明和可见光通信 (VLC)，面向 VLC 照明的 GaN 基白光发光二极管 (WLED) 引起了极大的兴趣。然而，传统荧光粉转换 WLED 的总带宽受到荧光粉寿命长、斯托克斯转移过程缓慢、电阻电容 (RC) 时间延迟和量子限制斯塔克效应 (QCSE) 的限制。在这里，通过采用自组装 InGaN 量子点 (QD) 结构，我们制造了具有可调相关色温 (CCT，从 1600 K 到 6000 K)、宽带光谱、中等显色指数 ( CRI) 为 75，并且在 72 A/cm2 的低电流密度下显着提高了调制带宽（最大 150 MHz）。与传统的 InGaN/GaN 量子阱 (QW) 结构相比，宽带光谱和高调制带宽归因于 InGaN QD 的不同局域态捕获载流子，具有缓解的 QCSE。我们相信这项工作中报告的方法将在 GaN WLED 中找到其潜在应用，并推动半导体照明-通信集成的发展。