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The responsivity and specific detectivity are critical figures of merits for organic photodetectors; however, it remains challenging to simultaneously enhance two such parameters, since enhancing external quantum efficiency corresponding to responsivities will inevitably increase leakage current and noises, resulting in decreased specific detectivity. To address such a trade‐off, an effective anode interfacial layer of 7,7,8,8‐tetracyanoquinodimethane (TCNQ) doped copper thiocyanate (CuSCN) is developed herein, which can enhance shunt resistance, increase depletion width, enhance hole extraction efficiency, as well as reduce trap density of states of organic photodetectors. The organic photodetectors based on doped CuSCN present a very low dark current density of 4.4 × 10−11 A cm−2 and an impressively high specific detectivity of 1.1 × 1014 Jones. As evidenced by X‐ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy measurements, the energy levels of the doped CuSCN:TCNQ film are deepened, associated with the occurrence of dopant bonding and charge transfer. In addition, it is found that increasing the delay time can suppress the hysteresis effects of current density–voltage characteristics of organic photodetectors and make the minimum dark current density obtainable at 0 V. These findings demonstrate the great potential of using molecular doping to adjust the anode interfacial layer for developing high‐performance organic photodetectors. [ABSTRACT FROM AUTHOR]

Rare earth doped down‐conversion (DC) materials, due to their unique spectral conversion characteristics, are promising candidates for narrow band solar‐blind ultraviolet (UV) light detection devices. Herein, an enhanced capture device for broadband solar‐blind UV light is constructed by combining an ordinary semiconductor with a DC spectrum converter, the essence of which is to introduce the appropriate alkali‐metal ions (Li+, Na+, and K+) into DC layer. Europium‐doped organic–inorganic composite films are used as spectral converters because of their excellent DC characteristic, which can convert broadband solar‐blind UV incident illumination into visible light suitable for capture by light dependent resistor (LDR). Interestingly, the spectral conversion efficiency is positively correlated with the capture ability of broadband solar‐blind UV photons. The introduction of alkali‐metal ions in the DC layer enhances the photon detection efficiency with an increase rate of around 200%, which is attributed to alkali‐metal ions changing the local crystal field symmetry around the Eu3+ emitter and distorting the matrix crystal of Y2O3, thus increasing the probability of intra‐4f electron transition. These results signify that the present rare‐earth doped DC luminescent materials are promising building blocks for assembly of high‐performance broadband solar‐blind UV detector. [ABSTRACT FROM AUTHOR]