DocumentCode :
58755
Title :
Modeling and Simulation of Organic Photodetectors for Low Light Intensity Applications
Author :
Popescu, B.V. ; Popescu, D.H. ; Lugli, Paolo ; Locci, S. ; Arca, Francesco ; Tedde, Sandro F. ; Sramek, Maria ; Hayden, Oliver
Author_Institution :
TUM Grad. Sch. & the Inst. for Nanoelectron., Tech. Univ. Munich, Munich, Germany
Volume :
60
Issue :
6
fYear :
2013
fDate :
Jun-13
Firstpage :
1975
Lastpage :
1981
Abstract :
In this paper, we investigate the dynamic response of two different bulk heterojunction organic photodetectors over a large illumination and frequency range. To our knowledge, there is no similar study that includes the nW/cm2 regime. Photocurrent transient measurements reveal that the interlayer at the hole-extracting electrode is critical for the device performance under ultralow illumination. Furthermore, we observe a nonlinear cutoff frequency behavior over the illumination range, which we attribute to interface-related phenomena. We perform a detailed simulation study of the transient response for the measured samples. Making use of a drift diffusion model that also takes into account charge trapping and detrapping effects, both in bulk and at material interfaces, we are able to successfully reproduce the measured transients. Based on our simulations, we propose an explanation for this effect: it can be attributed to the interplay between the potential landscape seen by the charge carriers and to the presence of a large concentration of interface trap states, as well as of fixed interface charges. The importance of smart interface engineering as a key factor for device optimization is also highlighted.
Keywords :
electrodes; interface states; lighting; optimisation; organic semiconductors; photodetectors; photoemission; transient response; bulk heterojunction organic photodetector; charge carrier; charge trapping; detrapping effect; device optimization; device performance; drift diffusion model; dynamic response; fixed interface charge; frequency range; hole-extracting electrode interlayer; illumination range; interface engineering; interface trap state; interface-related phenomena; low light intensity application; material interface; nonlinear cutoff frequency behavior; organic photodetector modeling; organic photodetector simulation; photocurrent transient measurement; transient response; ultralow illumination; Cutoff frequency; interface engineering; organic; photodetector bulk heterojunction; simulation; trap states;
fLanguage :
English
Journal_Title :
Electron Devices, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9383
Type :
jour
DOI :
10.1109/TED.2013.2259239
Filename :
6515596
Link To Document :
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