Berlin 2018 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 46: Poster Session IV

CPP 46.28: Poster

Mittwoch, 14. März 2018, 11:00–13:00, Poster A

Solution-processed Dual Wavelength Organic Near-Infrared Photodetectors — •Yazhong Wang, Zheng Tang, Bernhard Siegumund, Zaifei Ma, Johannes Benduhn, Donato Spoltore, and Koen Vandewal — Technische Universität Dresden, Nöthnitzer Str. 61, 01187 Dresden, Germany

Optical sensors that are capable of detecting photons at two or multiple specific wavelengths are highly interesting because they can identify target objects or materials much more precisely by detecting the reflected, transmitted or emitted photons at two or multiple characteristic wavelengths. In this work, optical simulations using Transfer Matrix Method (TMM) were performed on organic devices to achieve dual wavelength narrowband detection in the near-infrared spectral range of 700 ~ 1100 nm. The devices exploit charge-transfer (CT) states, formed at the interface of blended organic donating and accepting materials. Combined with a Fabry-Pérot resonant cavity, the CT absorption can be dramatically enhanced at certain wavelengths. Our results show that two detection wavelengths can be tuned independently from 650 to 1100 nm. The spectral resolution (full width at half maximum - FWHM) of the detection bands varies between 10 and 30 nm, and we achieved peak EQEs above 10%. A possible application of such photodetectors is moisture detection, where two of the characteristic absorption peaks of water are located at around 750 and 960 nm. By optimizing the thickness of the two photo-absorbing layers in a tandem device structure, the detection bands can be tuned to match with those two wavelengths for simultaneous and precise detection.