有機共軛高分子近紅外光學接近感測裝置

Conjugated polymer based near-infrared optical proximity sensor

陳恩禎(En-Chen Chen)

指導教授 ： 洪勝富 ； 孟心飛

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.2008.00692

摘要

目前光學接近感測器大部分由無機分子為材料，其製程困難，且不容易製作於可撓式基板上，若要應用於大面積感測時(如機器人的皮膚)，要一顆一顆嵌入，成本相當高。相對於此，有機分子具有可撓性，可製作於大面積軟性基板而應用於任合表面，其製程簡單並有低成本的潛力。但有機分子因材料特性，發光及吸光範圍大多為可見光波段，此波段進行接近感測時可偵測距離相當短。以紅外光製作光學接近感測器較不易被散射，偵測距離也較遠，而紅外有機發光二極體非常少見，固本創作研發紅外光之光學接近感測器可同時具有偵測距離較長即可製作於大面積可撓式基板之優點。
本裝置由近紅外有機發光二極體及有機吸收近紅外的光偵測器所組成，元件操作波長大概在700nm~850nm，在紅外有機發光二極體部分是由一層的波長轉換膜及可見光發光二極體所組成。近紅外的光偵測器是由等比例混合的P3HT(poly(3-hexylthiophene)及PCBM( [6,6]-phenyl-C61-butyric acid methylester )材料所製作。藉由兩種元件的結合，形成所謂的光學接近感測裝置。最後針對阻擋物不同表面顏色及粗操度，實際量測距離結果，有效接近感測可抵達20公分。

關鍵字

可撓式 ； 有機 ； 共軛高分子 ； 紅外光 ； 有機發光二極體 ； 轉換膜 ； 光偵測器 ； HASH(0x1d699520) ； HASH(0x1d6995c0)

並列摘要

Most commercial proximity sensors are made of inorganic materials with complicated fabrication process and the processing is not compatible with flexible substrates. It will also costly when large-area applications are required such as the skin of robots. On the contrary, it is easy for organic materials to be applied in large-area and flexible substrate due to their mechanic property. The organic materials have potential for easy fabrication process and low cost. However the emission and absorption range of organic materials are usually in the visible range. In the visible range the sensing distance is very short (~1cm). For proximity sensor the infrared light is commonly used due to longer sensing distance. It is, however, difficult for organic materials to emit or absorb infrared light. Our invention as reported in this thesis is to make an infrared organic proximity sensor through a color-conversion film. The advantages of our organic proximity sensor include both long sensing distance and large-area as well as flexible application.
A conjugated polymer optical proximity sensor which combines a polymer light-emitting diode and a polymer photodiode is demonstrated. The operation wavelength is in the near infrared spectrum 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 1,1-diethyl-2,2-dicarbocyanine iodide to a red 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 methylester. The detection distance is up to 19 cm for objects with various colors and roughness under ambient indoor lighting.

並列關鍵字

flexible ； organic ； conjugated polymer ； infrared ； light-emitting diodes ； color conversion layer ； photodetector ； P3HT(poly(3-hexylthiophene) ； PCBM( [6,6]-phenyl-C61-butyric acid methylester )

參考文獻

[2]. C.W. Tang， S.A. VanSlyke， Appl. Phys. Lett. 51 (1987) 913.

[4]. C. W. Tang, “Two-layer organic photovoltaic cell,” Appl. Phys. Lett. 48, 183 (1986).

[5]. G. Yu, K. Pakbaz, and A. J. Heeger, “Semiconducting polymer diodes: Large size, low cost photodetectors with excellent visible-ultraviolet sensitivity,” Appl. Phys. Lett. 64, 3422 (1994).

[6]. Kyungkon Kim, “Roles of donor and acceptor nanodomains in 6% efficient thermally annealed polymer photovoltaics” Appl. Phys. Lett. 90, 163511 (2007)

[7]. C. M. Yang, P. Y. Tsai, S. F. Horng, K. C. Lee, S. R. Tseng and H. F. Meng, J. T. Shy and C.F. Shu, Appl. Phys. Lett. 92, 083504 (2008)