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On the Origin of Dark Current in Organic Photodiodes
Author(s) -
Simone Giulio,
Dyson Matthew J.,
Weijtens Christ H. L.,
Meskers Stefan C. J.,
Coehoorn Reinder,
Janssen René A. J.,
Gelinck Gerwin H.
Publication year - 2020
Publication title -
advanced optical materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.89
H-Index - 91
ISSN - 2195-1071
DOI - 10.1002/adom.201901568
Subject(s) - dark current , photodiode , materials science , photodetector , optoelectronics , heterojunction , active layer , organic semiconductor , charge carrier , semiconductor , sensitivity (control systems) , biasing , quantum efficiency , reverse bias , layer (electronics) , nanotechnology , voltage , physics , quantum mechanics , electronic engineering , engineering , thin film transistor , diode
Minimizing the reverse bias dark current while retaining external quantum efficiency is crucial if the light detection sensitivity of organic photodiodes (OPDs) is to compete with inorganic photodetectors. However, a quantitative relationship between the magnitude of the dark current density under reverse bias ( J d ) and the properties of the bulk heterojunction (BHJ) active layer has so far not been established. Here, a systematic analysis of J d in state‐of‐the‐art BHJ OPDs using five polymers with a range of energy levels and charge transport characteristics is presented. The magnitude and activation energy of J d are explained using a model that assumes charge injection from the metal contacts into an energetically disordered semiconductor. By relating J d to material parameters, insights into the origin of J d are obtained that enable the future selection of successful OPD materials.