Comprehensive studies of response characteristics of organic photodetectors based on rubrene and C{sub 60}

Journal Article · Sat Jun 28 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4885078· OSTI ID:22304051

Yang, Dezhi; Xu, Kai; Zhou, Xiaokang; Wang, Yanping; Ma, Dongge ^[1]

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1. State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

We studied the transient response characteristics of organic photodetectors composing of high mobility materials of rubrene and C{sub 60}, respectively, as donor and acceptor. It was found that the response speed was limited by the delay time of both exciton diffusion and transit, and an anomalous phenomenon that the bandwidth decreases as the reverse bias increases was found for the first time. The investigation of frequency dependence at different device structures and light excitations demonstrated that the light absorption of rubrene prevents the photodetector from obtaining a fast response. With the help of magnetic field effect study, it was clearly elucidated that the slow diffusion time of the long lifetime triplet excitons generated from singlet fission in rubrene limited the bandwidth of the device. Moreover, the simulation of the response of photodetector under transient and steady state by exciton transport-diffusion equation showed that the exciton dissociation efficiency in rubrene increases more quickly than that in C{sub 60}, which should account for the negative dependence of bandwidth on the reverse bias in rubrene-based device.

• OSTI ID: 22304051
• Journal Information: Journal of Applied Physics, Vol. 115, Issue 24; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
DIFFUSION
DIFFUSION EQUATIONS
DISSOCIATION
EFFICIENCY
EQUIPMENT
EXCITATION
EXCITONS
FREQUENCY DEPENDENCE
FULLERENES
LIFETIME
MAGNETIC FIELDS
NANOSTRUCTURES
ORGANIC SEMICONDUCTORS
PHOTODETECTORS
SIMULATION
STEADY-STATE CONDITIONS
TIME DELAY
TRANSIENTS
VISIBLE RADIATION