兩性離子界面修飾的高增益有機光探測器研究
發(fā)布時間:2018-04-27 03:23
本文選題:兩性離子 + 有機光探測器; 參考:《哈爾濱工業(yè)大學(xué)》2017年碩士論文
【摘要】:有機光探測器具有質(zhì)量輕,可以采用溶劑成膜,大面積低成本、柔性基底上制備的優(yōu)點,而且共軛聚合物材料還可以通過添加或減少支鏈控制其溶解性和帶隙寬度調(diào)節(jié)光電特性,被廣泛的應(yīng)用在國防、通信、環(huán)境監(jiān)測、遙感控制、化學(xué)/生物傳感和航空航天等領(lǐng)域。然而,傳統(tǒng)高增益有機光探測器是人為的在聚合物表面設(shè)計納米顆粒陷阱誘導(dǎo)電荷的二次注入,很難同時的增加響應(yīng)度和響應(yīng)速度。而有機材料的制備過程中必不可少的會引入缺陷,這些缺陷也會捕獲電子,只是有機材料的內(nèi)部陷阱較少,不足以在外部電場的作用下產(chǎn)生高增益。本文以此為出發(fā)點,將有機聚合物材料內(nèi)部的陷阱與有機-無機異質(zhì)結(jié)相結(jié)合制備了高增益光探測器。界面修飾材料可以有效的改變電極和活性層之間的界面接觸使器件性能顯著提高,本文采用兩性離子材料wc-1和wc-2對以PCE-10共混PC71BM的光探測器進(jìn)行了界面修飾,活性層旋涂厚度約為200 nm,熱處理方式是旋涂活性層后靜置12 h后110℃加熱20 min。wc-2以濃度0.75 mg/m L,wc-1以1.5 mg/m L濃度旋涂在ITO上進(jìn)行界面修飾后器件的外量子效率增加12%以上、暗電流下降一個數(shù)量級、器件的探測率達(dá)到1013 Jones、瞬態(tài)響應(yīng)時間達(dá)到微妙級、線性動態(tài)范圍(LDR)超過85 d B。因PCE-10材料內(nèi)部陷阱含量太低,器件在外部偏壓作用下增益并不明顯。據(jù)此,使用賴氨酸修飾含有較多陷阱的PBDTT-DPP共混PC71BM材料制備了在室溫0.8 V偏壓下外量子效率3500%、比探測率值高于無機Si探測器達(dá)到了1014 Jone、響應(yīng)時間快、線性度大的高增益光探測器器件。高增益有機光探測器件的工作原理是Mo O3/Al復(fù)合層和活性層給體材料PBDTT-DPP材料接觸后,電子被存在于其中的陷阱所捕獲,在兩相交界處形成了空間電荷限制區(qū)(SCR),在器件內(nèi)部形成了N-P-N雜化異質(zhì)結(jié)結(jié)構(gòu),分別是PCBM/PBDTT-DPP的有機本體異質(zhì)結(jié)(N-P)和PBDTT-DPP/Mo O3的有機-無機異質(zhì)結(jié)(P-N),利用器件內(nèi)部光生載流子產(chǎn)生的微小電流作為開關(guān)誘導(dǎo)外部電流注入使器件在正偏壓下具有高增益現(xiàn)象。根據(jù)這個原理,如果人為的控制聚合物材料中的陷阱密度并將其應(yīng)用到探測領(lǐng)域,高增益光探測器件必將獲得突破性的發(fā)展。
[Abstract]:Organic photodetectors have the advantages of light weight, solvent film formation, large area, low cost and flexible substrate. Moreover, conjugated polymer materials can control their solubility and bandgap width by adding or reducing the branching chain, which can be widely used in defense, communication, environmental monitoring, remote sensing control. Chemical / biological sensing and aerospace. However, the conventional high gain organic photodetectors are artificially designed on the polymer surface to create nanoparticles trap induced charge secondary injection, it is difficult to simultaneously increase the responsivity and response speed. However, defects will be introduced in the preparation of organic materials, and these defects will trap electrons. However, the internal traps of organic materials are less, which is not enough to produce high gain under the action of external electric field. In this paper, a high gain photodetector was prepared by combining the trap of organic polymer material with the organic inorganic heterojunction. The interfacial modification material can effectively change the interface contact between the electrode and the active layer to improve the performance of the device. In this paper, wc-1 and wc-2 are used to modify the interface of the photodetector with PCE-10 blend PC71BM. The active layer spin-coating thickness is about 200nm.The heat treatment method is that the active layer is spin-coated for 12 h, then heated at 110 鈩,
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