Flexible Filter‐Free Narrowband Photodetector with High Gain and Customized Responsive Spectrum

Abstract

Conventional narrowband photodetection is enabled by coupling broadband photodetectors with complex optical filters. The recently reported charge collection narrowing, an alternative filter‐free strategy, attains very narrowband photodetection at the sacrifice of sensitivity. Herein, a new strategy is proposed to customize the responsive spectrum with high gain by using dye molecules with intrinsically versatile and narrowband absorption. The device configuration is organic dye/Zn0.9Mg0.1O nanoparticles/graphene, where the organic dye serves as the narrowband absorber, graphene serves as the fast carrier transport channel, and Zn0.9Mg0.1O nanoparticles play a triple role of enhancing dye loading, suppressing dye aggregation and blocking charge back recombination. A high responsivity of 8 × 103 A W−1 is thus obtained at a 530 nm response peak with a 60 nm full‐width at half maximum, a four orders of magnitude increase in sensitivity compared to the best narrowband photodetectors reported to date under the comparable electric field. Organic dyes with dual‐band absorption to demonstrate narrowband photodetectors with customized responsive spectrum are further implemented. The approach opens the way to the realization of efficient flexible narrowband photodetection for electronic skin and wearable electronic applications.

In Situ Formed Gradient Bandgap‐Tunable Perovskite for Ultrahigh‐Speed Color/Spectrum‐Sensitive Photodetectors via Electron‐Donor Control

“…All photodetectors exhibit a fast response toward all light with visible wavelengths. A response time down to 71 ns is obtained, several orders of magnitude lower when compared with that of other filterless color/spectrum‐sensitive photodetectors,5,9–14,16,19,45–47 (Table S5, Supporting Information), which can be further accelerated by reducing the device area. It should also notice that our device which works at the self‐powered mode shows higher responsivity than other color detectors based on perovskite, even all of them required additional voltage bias.…”

“…To parse spectrum, two strategies are available. One is the optical solution which includes: 1) using color filter or stacked absorption layers to construct laminated device,2–4 2) choosing narrowband absorption semiconductor as absorber,5 3) using optical interference or plasmonic effect to enhance responsivity of the chosen wavelength,6,7 4) using prism and mechanical system to parse spectrum 8. The other is electronic solution which mainly relies on charge collection narrowing that is enabled by controlling surface recombination or self‐trapped states 9–11.…”

Recent Progress on Photomultiplication Type Organic Photodetectors

“…Tang et al. proposed a general strategy of customizing the responsive spectrum by utilizing dye molecules with intrinsically versatile and narrowband absorption, achieving the high gain narrowband photo‐detection compatible with flexible electronics . This strategy relies on the controlled adsorption of organic dyes onto the Zn 0.9 Mg 0.1 O nanoparticles (NPs), in which the dye–dye coupling and the π‐bond resonance between dye molecule and graphene are suppressed by the sandwiched Zn 0.9 Mg 0.1 O NP relay layer, thereby maintaining the intrinsic narrowband character of the photosensitizer dyes ( Figure a–d).…”

“…The channel length is 200 µm and the width is 1 mm. All panels reproduced with permission . Copyright 2017, Wiley‐VCH.…”

Efficiency and spectral performance of narrowband organic and perovskite photodetectors: a cross-sectional review

“…EQE values (in primary photocurrent mode) in the 50%-80% range have been achieved throughout the visible range [11, 22, 46, 57-59, 61, 69-72, 95, 120, 121, 128, 129], with associated spectral widths of around 90-150 nm. Operation in secondary photocurrent mode has also delivered large EQE values [27,[30][31][32]131], typically in the 10 3 %-10 4 % range, and up to ≈2·10 5 in one instance [131]. Ultranarrowband photodetectors (FWHM EQE <50 nm) have also been obtained in a conspicuous number of works [25, 30-32, 42, 54, 65, 73, 75, 76, 80-82, 86, 136-139].…”