可撓式磁控變色量子點發光二極體

Abstract

本研究提出一種可應用於可見光通訊的新型可撓式磁控變色發光二極體，這種新型的發光二極體會根據不同外加磁場產生不同的發射光譜。當施加不同強度的外加磁場時，這個發光二極體會發射不同強度比例 540 nm以及630 nm峰值的可見光。藉此，發光二極體能夠比起單純依靠快速地閃爍在單位時間內傳遞更多訊息。整個元件的製作經由合理的設計並且選取適當的材質來符合能帶排列，將兩種不同發光頻譜的量子點混和在一起，並與電子傳輸層、電洞傳輸層形成夾層結構，最後再轉印一層靈敏度及高的金字塔微結構磁感測器。元件的每一層都能使用簡單溼式製程來完成。這個元件擁有低工作電壓、可撓可穿戴以及簡單製程等優點，在可穿戴行動光通訊中能勝任傳輸、加密、顯示等等重要的功能。

This study presents a new approach of flexible magnetic-field-controlled light-emitting diode (LED) towards visible light communication. This new LED will change its emission spectrum under an applied magnetic field. With different magnitude of magnetic field, this LED has different peak intensity ratio of 540 nm and 630 nm which can transmit extra message outside of the high frequency on-off flickering of LED. The LED was made by a rational design with an appropriate band alignment for all the constituent layers. They consist of a quantum dots layer with two kinds of quantum dots that can emit different wavelengths, which was sandwiched by electron and hole transport layers. Finally, a sensitive pyramid-microstructure magnetic sensor was transferred on it. All the layers can be fabricated by solution-based processes. Combining the advantages of low working voltage, flexibility and simple fabrication process, this device shows promising usage in wearable, mobile optical communication as a data emitter, encoder and displayer.