Ultraviolet and visible dual-narrowband photomultiplication type organic photodetectors

초록

"Series of dual-narrowband photomultiplication type organic photodetectors (PM-OPDs) were developed with a structure of P-TPD:F8BT (3:1, w/w)/Glass/ITO/PEDOT:PSS/P3HT:PC71BM (100:1, w/w)/semi-transparent Ag. The external 1 μm thick P-TPD:F8BT layer is employed as organic filter layer (OFL) to absorb photons with wavelength below 500 nm. The external quantum efficiency (EQE) spectra of dual-narrowband PM-OPDs can be optimized by adjusting the thickness of semi-transparent Ag layer. The PM-OPDs exhibit UV narrowband response with full width at half maximum (FWHM) of 40 nm and peak EQE of 3370 % at 320 nm under top illumination. Meanwhile, the PM-OPDs show visible narrowband response with FWHM of 44 nm and peak EQE of 3350 % at 610 nm under bottom illumination. The switchable narrowband response range of PM-OPDs can be well explained from the trapped electron distribution near Ag electrode under top or bottom illumination. The signal-to-noise ratio (SNR) and specific detectivity (D*) of dual-narrowband PM-OPDs can be efficiently improved by replacing PEDOT:PSS with TPAFS-7TMA as interfacial layer. An optical system was built by employing the optimal dual-narrowband PM-OPDs to successfully demonstrate demultiplexing weak intermixed optical signals. © 2025 Elsevier B.V.

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