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Performance of bulk-heterojunction organic photodetectors. 陳詠升. OUTLINE. 介紹 THE BULK-HETEROJUNCTION PERFORMANCE OF ORGANIC PHOTODETECTORS CONCLUSION 參考文獻. 介紹. In the near future organic photodetectors will be found in applications like imaging and sensing
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Performance of bulk-heterojunction organic photodetectors 陳詠升
OUTLINE • 介紹 • THE BULK-HETEROJUNCTION • PERFORMANCE OF ORGANIC PHOTODETECTORS • CONCLUSION • 參考文獻
介紹 • In the near future organic photodetectors will be found in applications like imaging and sensing • This leads to a high sensitivity to light. Organic photodetectors with low dark currents, external quantum eficiencies of 80% in the visible,linearity over several decades and fast transient behavior are demonstrated
BULK-HETEROJUNCTION 異質接面定義為:用兩個不同半導體所組成之接面 LUMO LUMO HOMO HOMO P3HT PCBM Principle of bulk-heterojunction: The photon generates an exciton. The lower LUMO of PCBM compared to P3HT forces the electron to transfer to the LUMO of PCBM.
Image of the surface of the organic semiconductor(PSHT/PCBM). A substructure with a dimension in the tens of nanometers is observed.
TOP Electrode(Ca/Ag) Organic Semlconductar (P3HT/PCBM) Pedot Bottom Electrodr(ITO) Glass Substrate Device stack beginning h.om the substrate: bottom electrode (to extract holes), hole transportation layer (Pedot),absorber layer (bulk-heterojunction), top electrode (to extract electrons)
I-V-characteristics under illumination and in darkness:Applying a small reverse bias (-OSV) the difference is about 5 orders of magnitude (desired signal for light detection) under illumination with lsun (100W/em2). The difference decreases slightly with increasing the applied reverse bias.
Io :飽和電流 V :外加偏壓 I:通過二極體的電流 n :理想係數 KB :光譜 T:溫度 RS :並聯電阻
CONCLUSION • buk-heterojunction的organic photodetectors有好的外部量子效率 • 對光的檢測敏感度高反應時間快,可以應用在攝影機或照像機、醫學儀器上
參考文獻 • http://zh.wikipedia.org/w/index.php?title=%E5%AF%8C%E5%8B%92%E7%83%AF&variant=zh-tw • http://tw.knowledge.yahoo.com/question/question?qid=1508011310024