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Performance of bulk-heterojunction
organic photodetectors
陳詠升
OUTLINE
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介紹
THE BULK-HETEROJUNCTION
PERFORMANCE OF ORGANIC
PHOTODETECTORS
CONCLUSION
參考文獻
介紹
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In the near future organic photodetectors will be
found in applications like imaging and sensing
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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
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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
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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