以自發性垂直相分離現象提升高分子太陽能電池及光偵測器特性

Abstract

我們已經初步證實一種與金屬鋁反應後可形成良好的接觸之高分子，可以經由自發 性垂直於基板方向的相分離生成於高分子混合物之表面，此方法不但可以簡化元件製 程，也可提升元件之效率與穩定度。「以自發性垂直相分離現象提升高分子太陽能電池 及光偵測器特性」之研究計劃將系統性地研究此垂直相分離現象及對高分子太陽能電 池及光偵測器特性的影響。除了元件製作與光電特性量測之外，將量測元件的生命期 和穩定度與研究元件的衰變機制，高分子薄膜型態也將以原子力顯微鏡、穿透式電子 顯微鏡、及雷射掃描共軛焦顯微鏡等方式研究，材料的深度剖面也將以二次離子質譜 儀研究，相圖則從掃描式熱差計或光散射量測建立，也將以新材料及不同分子量的高 分子研究其材料的影響。我們也將在陽極部分製作可經垂直相分離產生之修飾層，更 進一步提升元件效率與穩定性，最後，此方式也將被應用於製作對有機光偵測器。預 計成功執行本計劃後高分子太陽能電池及光偵測器的效率與元件生命期及穩定性將被 大幅改善。

We have found that poly(ethylene glycol) (PEG), which will react with Al to form an excellent contact at the cathode, spontaneously vertically phase separated in the polymer solar cells. The “spontaneous vertical phase separation for improving the performance of polymer solar cells and photodetectors” research project will systematically investigate such vertical-phase-separation and its effects on the device performance of polymer solar cells and photodetectors. The lifetime of the devices will be measured and the device decay mechanism will be also studied. The morphology of the polymer thin films will be examined by atomic force microscopy, scanning electron microscopy, and laser scanning confocal microscopy. The depth profile will be studied by secondary ion mass spectrometry. The phase diagram of the polymer mixtures will be obtained from the results of differential scanning calorimetry and/or light scattering measurement. Different materials, such as PEG with different molecular weight, and new semiconducting materials will be used to fabricate the devices. The mechanism of the phase separation will be thoroughly studied. Further, interlayers formed on the anode side will be also fabricated to further improve the device performance. Finally, the effect of such vertical phase separation on the performance of polymer photodiodes will be also investigated. The device efficiency and device lifetime of both polymer solar cells and photodetectors are anticipated to be improved significantly after the success of this project.