The continuous tuning of the emission spectrum of a single light-emitting diode (LED) by an external electrical bias is of great technological significance as a crucial property in high-quality displays, yet this capability has not been demonstrated in existing LEDs. Graphene, a tunable optical platform, is a promising medium to achieve this goal. Here we demonstrate a bright spectrally tunable electroluminescence from blue (∼450 nm) to red (∼750 nm) at the graphene oxide/reduced-graphene oxide interface. We explain the electroluminescence results from the recombination of Poole-Frenkel emission ionized electrons at the localized energy levels arising from semi-reduced graphene oxide, and holes from the top of the π band. Tuning of the emission wavelength is achieved by gate modulation of the participating localized energy levels. Our demonstration of current-driven tunable LEDs not only represents a method for emission wavelength tuning but also may find applications in high-quality displays.

中文翻译：

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一种基于光谱可调的全石墨烯柔性场效应发光器件。

通过外部电偏压对单个发光二极管（LED）的发射光谱进行连续调谐作为高质量显示器中的关键属性具有重大的技术意义，但是这种能力尚未在现有的LED中得到证明。石墨烯是一种可调节的光学平台，是实现该目标的一种有前途的媒介。在这里，我们证明了在氧化石墨烯/还原氧化石墨烯界面处，从蓝色（〜450 nm）到红色（〜750 nm）的光谱可调光致发光。我们解释了由Poole-Frenkel发射电离的电子在半还原氧化石墨烯和π谱带顶部的空穴引起的局部能级复合时产生的电致发光结果。发射波长的调谐是通过对参与的局部能级进行门调制来实现的。