Regensburg 2019 – wissenschaftliches Programm
HL 45.22: Poster
Donnerstag, 4. April 2019, 18:30–21:00, Poster E
Tunable Polymer Photodetectors: Towards Low Dark Current and High Detectivity — •Shen Xing, Erjuan Guo, Hans Kleemann, and Karl Leo — Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, 01062 Dresden, Germany
Photodetectors with a high detectivity as well as a high spectral selectivity are essential for high-resolution image sensor arrays. Here, we introduce a method for tuning the polymer photodetector (PPD) spectra without an optical filter. The devices have a simple planar junction architecture with the photoactive layer being a sequentially solution-processed film of PC71BM onto the pre-deposited bottom layer of doped P3HT. We demonstrate a redshift of response peak of around 100 nm in the red light range (645-745 nm) by tuning the PTB7 doping ratio in P3HT layer. In addition, for optimized doping ratio in P3HT, the external quantum efficiency of the response peak is doubled and the dark current density is simultaneously reduced by two orders of magnitude, leading to a maximum detectivity over 1012 Jones. This design concept allows for response tuning and is generic for other spectral windows.