結合高分子發光二極體以及高分子光偵測器來達成高分子紅外線距離感測器

Infrared polymer proximity sensor by the combination of a polymer light-emitting diode and a polymer photodetector

朱家宏(Chia-Hong Chu)

指導教授 ： 洪勝富 ； 夢心飛

國立清華大學/電機資訊學院/電子工程研究所/碩士(2008年)

https://doi.org/10.6843/NTHU.2008.00705

摘要

有機高分子光電元件由於具有成本低廉、製成簡易、可大面積並成膜於軟性基板等優勢。正好符合智能化機器人的感測皮膚之需求。傳統的無機紅外線距離感測元件並無法在軟性基板上以陣列方式製程。相反的，對於有機發光二極體以及有機光偵測元件而言，在軟性基板上形成高密度矩陣將是很容易達成的事。
本論文之高分子距離感測器是結合了高分子發光二極體以及高分子光感測器，並且操作在波長為700nm到800nm的近紅外光範圍。紅外光的發射是將可見光高分子發光二極體結合ㄧ紅外光轉換膜將可見光轉換為紅外光，轉換模是由PVP和紅外線染料混合而成。而光偵測器是採用P3HT和PCBM混合的donor-acceptor系統，藉由吸收紅外光而激發donor(P3HT)的共價帶上的電子躍遷至acceptor(PCBM)的傳導帶而行成charge-transfer exciton，透過此機制來吸收被偵測物反射回來的紅外光並產生光電流。
在室內環境下，對於不同顏色以及表面粗糙度的偵測物做距離量測，而偵測距離會隨著偵測物的顏色以及表面粗糙度而有所變化。當發光二極體偏壓在9V時，最長偵測距離可達19cm。最後並藉由一具有放大訊號且有帶通濾波功能的電路來處理所偵測的訊號，提升元件的應用價值。

關鍵字

高分子 ； 機器人 ； 距離感測 ； 紅外光 ； 發光二極體 ； 光偵測器

並列摘要

Organic optoelectronic devices based on conjugated polymers attract a lot of interests in the past decade due to the possibilities of low cost large-area solution process on flexible surfaces.Such unique properties are highly desirable for the development of sensitive skin for a moving machine like robot or car. The conventional proximity sensor based on inorganic near infrared light-emitting diodes and photo-detectors can not be integrated by monolithic fabrication as an array on flexible substrate which is essential for robots and other machine surfaces. Contrarily it is rather easy to fabricate polymer light-emitting diodes (PLED) and polymer photo-detectors on plastic substrates with a high pixel density.
A proximity sensor which combines a polymer light-emitting diode and a polymer photodiode is presented. The operation wavelength is in the near infrared from 700 nm to 850 nm. The infrared emission is obtained by adding a color conversion film of polyvinylpyrrolidone polymer matrix blended with infrared dye to a visible-light polymer lightemitting diode. The photodetector relies on the direct charge-transfer exciton generation in a donor-acceptor polymer blend of poly(3-hexylthiophene) and (6,6)-phenyl-C61-butyric acid methyl ester.
When the PLED is biased at 9 V the reflected light is strong enough and the detection distance is up to 19 cm for objects with various colors and roughness under ambient indoor lighting.

並列關鍵字

polymer ； robot ； proximity sensor ； infrared ； PLED ； photodetector

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