摻雜近紅外光染料之有機光偵測器

Abstract

本論文利用摻雜區域為近紅外光之染料於有機太陽二極體元件中，可增加元件的在700nm至900nm吸收光譜。由於元件中載子容易被近紅外光染料所捕獲，故元件在逆向偏壓時，受捕獲的載子會因為誘發電場使得另種電荷的注入能障降低而形成電流增益。利用電流增益的效應，可以增加光偵測器的響應率。達到高響應度。我們也發現電流增益的開啟電壓並不會因光強度改變而改變，使元件有較好的穩定度。同時光電流與光強度的關係在逆向偏壓5V時， 值為1.16。另外摻雜濃度越高，開啟電壓越小，光電流增益的現象越明顯，而元件厚度並不會改變開啟電場。最後從原子力顯微鏡可知暗電流與表面形貌有關，當表面越粗糙，元件的暗電流也越大。

Through Doping of Near-IR(NIR) materials in organic Photodiodes, the absorption of the device was extended into long wavelength region. Because the NIR dye can trap the charges easily, the trapped carrier will induce an electric field and decrease the injection barrier of the apposite charges. Therefore, high photocurrent multiplication was achieve at higher reverse bias. The turn on voltage of the photomultiplication did not depend on the light intensity. However, the degree of phase separation and the thickness of active layer significantly affected the turn on voltage. Finally, we found that the dark current increased with the surface roughness of the active layer.