本篇論文構想為使用全有機(Organic)材料系統製作半導體元件，結合有機太陽能電池(Organic photovoltaic, OPV)以及有機電激發光二極體(Organic light emitting diode, OLED)之特性製作薄膜型式之光轉換元件，其主要功能為吸收紅外光(長波長)影像，經由元件內部光→電→光的轉換，向外輸出綠色可見光(短波長)影像。因應吸收波段的需要，本篇論文採用氯鋁酞菁(Chloroaluminum phthalocyanine, ClAlPc)混合碳七十(C70)作為有機上轉換元件之感光單元，並以Ir(ppy)3綠色磷光OLED系統作為放光單元。
首先以標準OPV元件驗證此新型光吸收層對於近紅外光(Near-infrared, NIR)具備良好的光電響應及優秀的載子拆解能力；而後藉由元件結構設計，實現光吸收層可分別應用於上轉換元件之電洞供應及電子供應端，透過元件光電特性量測得最高上轉換效率為6.3%(W/W)，並採用最佳結構製作穿透式元件於夜視環境作紅外線成像之測試，所得最高影像解析度超過600 dpi，證明使用ClAlPc:C70此新型光吸收層之上轉換元件不僅具有高效率的光轉換能力，更具備高解析度的成像品質。
最終藉由電洞供應及電子供應元件之結構原理分析與光電特性數據，論證其暗電流主因來自於多數載子之反向貢獻，並藉由優化多數載子侷限介面與增加客發光體分子形成之載子陷阱態，達成電流增益接近90,000倍、最高上轉換效率6.1%(W/W)之高效能有機上轉換元件。

This thesis have demonstrated an all-organic thin-film optical up-conversion device by connecting organic photovoltaic (OPV) device and organic light-emitting diode (OLED) in series. The basis working principle of the up-conversion device is to absorb near-infrared (NIR) light and emits visible light that depends on materials used in OLED. The realistic functionality is to transform invisible light into visible image, such as night-vision or vein-eye applications. Because of the requirement of an OPV device with NIR-absorbing property, we used chloroaluminum phthalocyanine (ClAlPc) as a donor and C70 as an acceptor to fabricate the optical-sensing component, charge-generation layer (CGL). An OLED with a green light output is fabricated using Ir(ppy)3 phosphorescent material.
At first, the optimization of ClAlPc:C70-based OPV device exhibits a high external quantum efficiency in the NIR wavelength range, thus showing the potential of absorbing NIR light for generating charges that OLED requires. In addition, by carefully designing the device structure, the CGL can generate both holes and electrons and inject them into OLED for recombining electrons and holes originated from the electrode, respectively. The optimal upconversion efficiency of 6.3% in W/W is achieved. The transparent thin-film up-conversion device is successfully used in night-vision application and exhibits a high image resolution exceeding 600 dpi, demonstrating that the up-conversion device based on ClAlPc:C70 CGL can not only efficiently convert photons to charges but also having a high image quality.
Because of the ambipolar property of the CGL, we find that the dark current is primarily originated from the majority charge. The reduction in dark current can be realized by confining the majority charges at the interface and increase the dopant concentration in OLED, thus the current gain of over 90,000 and upconversion efficiency exceeding 6.1% in W/W are achieved.

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