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.

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Heterojunctions based on low dimensional semiconducting materials are one of the most promising alternatives for next-generation optoelectronic devices. By choosing different dopants in high-quality semiconducting nanomaterials, p-n junctions can be realized with tailored energy band alignments. Also, p-n bulkheterojunctions (BHJs) based photodetectors have shown high detectivity because of the suppressed dark current and high photocurrent, which are due to the larger built-in electric potential within the depletion region and can significantly improve the quantum efficiency by reducing the carriers' recombination. In this work, PbSe quantum dots (QDs) blended with ZnO nanocrystals (NCs) were used as the n-type layer, while CsPbBr 3 NCs doped with P3HT were used as the p-type layer; as a result, a p-n BHJ was formed with a strong built-in electric field. Consequently, such a kind of p-n BHJ photodetector ITO/ZnO/PbSe:ZnO/CsPbBr 3 :P3HT/P3HT/Au showed a high ON/OFF current ratio of 10 5 with a photoresponsivity of 1.4 A/W and specific detectivity of 6.59 × 10 14 Jones under 0.1 mW/cm 2 532 nm illumination in self-driven mode. Moreover, the simulation performed by TCAD also agrees well with our experimental results, and the underlying physical mechanism for enhanced performance is discussed in detail for this type of p-n BHJ photodetector.