Self-powered broadband photodetectors exhibit excellent self-powered and wide-band photoresponse from visible to infrared region and attract enormous attention due to their promising applications in imaging, sensing, and optical communication. PbSe colloidal quantum dots (CQDs) and halide perovskites nanocrystals (NCs) are commonly used for photodetectors due to their strong absorption capability, tunable bandgap, and high aspect ratio. However, due to suffering from low charge carrier mobility and high trap density, the performance of individual PbSe CQDs and perovskites-based photodetectors is not satisfactory. Integration of PbSe CQDs with inorganic mixed-halide perovskite nanomaterials can provide an opportunity to overcome these drawbacks. In this work, a hybrid nanocomposite of PbSe CQDs blended with all-inorganic mixed halide perovskite NCs is integrated to fabricate bulk-heterojunction-based high-performance photodetectors. The transportation of photogenerated carriers is enhanced by employing electrons-and holes-extracting layers. As a result, the photoresponsivity of 6.16 A W −1 and a specific detectivity of 5.96 × 10 13 Jones with an ON/OFF current ratio of 10 5 is obtained for bulk-heterojunction photodetector ITO/ZnO/PbSe:CsPbBr 1.5 I 1.5 /P3HT/Au in the self-powered mode. Meanwhile, the device performance of the fabricated photodetector is numerically simulated by using Technology Computer-Aided Design software, and the physical mechanisms for photogenerated carriers' transportation are discussed in detail.

Narrow band-gap colloidal quantum dots (CQDs) are promising materials for flexible electronic, such as infrared light photodetectors and solar cells.

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The micro-luminescence spectra of the diluted magnetic semiconductor (DMS) can reflect the spin-exciton interaction and related relaxation process. Here the micro-photoluminescence (micro-PL) spectra and PL lifetime measurements have been done on an individual ferromagnetic (FM)-coupled cobalt (Co) doped zinc selenide (ZnSe) nanowire. There occurs a double-peak profile in its near bandedge emission spectrum: the first peak is from free exciton (FX) and the second comes from magnetic polaron (MP). In their temperature dependent PL spectra, the MP emission peak demonstrates obviously temperature-independent behavior, in contrast to the behaviors of FX and reported exciton MP in nanobelt. It is found that in this Co(II) doped ZnSe nanowires, this MP's temperature-independent emission is related to the coupling between exciton and a FM nanocluster (↑↑↓). The nanocluster is likely due to the interaction of Se vacancies of the wide bandgap semiconductors with the antiferromagnetic (AFM) arrangement transition metal (TM) ions in these Se-deficient Co doped ZnSe nanowires. These results reflect that the AFM coupling TM ions pair can give rise to FM behavior with the involvement of positive charge defect, also indicating that the micro-luminescence detection can be used to study the magnetic coupling in DMS.