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2D perovskites are relatively stable but possess poor charge transport compared to 3D perovskites. To boost charge transport, novel 2D perovskites mixed with 3D perovskites are developed, where Pb²⁺are partially substituted by the heterovalent neodymium cations (Nd³⁺) within both 2D and 3D perovskites (termed Nd³⁺‐substituted 2D:3D mixed perovskites. Systematical studies reveal that the Nd³⁺‐substituted 2D:3D mixed perovskites possess larger crystals, superior crystallinity, suppressed non‐radiative charge recombination, and enhanced and balanced charge transport compared to the 2D:3D mixed perovskites. As a result, perovskite photovoltaics based on the Nd³⁺‐substituted 2D:3D mixed perovskites exhibit a power conversion efficiency of 22.11%, a photoresponsibility of over 700 mA W⁻¹, a photodetectivity of 4.29 × 10¹⁴ cm Hz^1/2 W⁻¹, a linear dynamic range of 165 dB at room temperature, and dramatically boosted stability. These results demonstrate that, a facile way is developed to realize high‐performance perovskite photovoltaics through partially heterovalent substituted Pb²⁺by Nd³⁺within 2D:3D mixed perovskites.

Polymer solar cells (PSCs) with a bulk heterojunction (BHJ) device structure have incredible advantages, such as low‐cost fabrication and flexibility. However, the power conversion efficiency (PCE) of BHJ PSCs needs to be further improved to realize their practical applications. In this study, boosted PCEs from PSCs based on BHJ composites incorporated with Fe₃O₄magnetic nanoparticles (MNPs), aligned by an external magnetic field (EMF), are reported. It is found that the coercive electric field within the Fe₃O₄MNPs generated by the EMF has a strong and positive influence on the charge generation, which results in a more than 10% increase in free charge carriers. Moreover, the coercive electric field speeds up the charge carrier transport and suppresses charge carrier recombination within PSCs. In addition, a shortened extraction time makes charge carriers more likely to make it to the electrodes. As a result, more than 15% enhancement in PCE is observed from the PSCs based on the BHJ composite incorporated with the Fe₃O₄MNPs and the EMF as compared with that based on the BHJ composite thin film. This work indicates that the incorporation of MNPs and the EMF is a facile way to enhance the PCEs of PSCs.

Perovskite solar cells in which 2D perovskites are incorporated within a 3D perovskite network exhibit improved stability with respect to purely 3D systems, but lower record power conversion efficiencies (PCEs). Here, a breakthrough is reported in achieving enhanced PCEs, increased stability, and suppressed photocurrent hysteresis by incorporating n‐type, low‐optical‐gap conjugated organic molecules into 2D:3D mixed perovskite composites. The resulting ternary perovskite–organic composites display extended absorption in the near‐infrared region, improved film morphology, enlarged crystallinity, balanced charge transport, efficient photoinduced charge transfer, and suppressed counter‐ion movement. As a result, the ternary perovskite–organic solar cells exhibit PCEs over 23%, which are among the best PCEs for perovskite solar cells with p–i–n device structure. Moreover, the ternary perovskite–organic solar cells possess dramatically enhanced stability and diminished photocurrent hysteresis. All these results demonstrate that the strategy of exploiting ternary perovskite–organic composite thin films provides a facile way to realize high‐performance perovskite solar cells.

The photocurrent multiplication (PM) effect has been used to boost the device performance of polymer‐based photodetectors (PDs), but its origin is rarely addressed. In this study, the origins of the PM effect in polymer PDs based on the P3HT:PC₇₁BM bulk heterojunction (BHJ) composite thin film, where P3HT is poly(3‐hexylthiophene), and PC₇₁BM is [6,6]phenyl‐C₇₁‐butyric acid methyl ester, through both computational simulation and experimental investigation are reported. Systematic studies indicate that two key factors play an important role in the realization of the PM effect in polymer PDs. One factor is the work function of the metal electrode, and the other is the PC₇₁BM aggregations at the interface between the P3HT:PC₇₁BM BHJ composite thin film and the metal electrode. Moreover, the results from both experimental and computational simulation indicate that the values of the current density under light illumination minus the current density in the dark of polymer PDs are increased simultaneously along with the reduction of the thickness of the P3HT:PC₇₁BM BHJ composite thin film. The results provide an understanding of the PM effect in polymer PDs and guidance for the development of high‐performance polymer PDs based on BHJ composite thin film.

Room‐temperature solution‐processed flexible photodetectors with spectral response from 300 to 2600 nm are reported. Solution‐processed polymeric thin film with transparency ranging from 300 to 7000 nm and superior electrical conductivity as the transparent electrode is reported. Solution‐processed flexible broadband photodetectors with a “vertical” device structure incorporating a perovskite/PbSe quantum dot bilayer thin film based on the above solution‐processed transparent polymeric electrode are demonstrated. The utilization of perovskite/PbSe quantum dot bilayer thin film as the photoactive layer extends spectral response to infrared region and boosts photocurrent densities in both visible and infrared regions through the trap‐assisted photomultiplication effect. Operated at room temperature and under an external bias of ‐1 V, the solution‐processed flexible photodetectors exhibit over 230 mA W^‐1responsivity, over 1011 cm Hz1/2/W photodetectivity from 300 to 2600 nm and ≈70 dB linear dynamic ranges. It is also found that the solution‐processed flexible broadband photodetectors exhibit fast response time and excellent flexibility. All these results demonstrate that this work develop a facile approach to realize room‐temperature operated ultrasensitive solution‐processed flexible broadband photodetectors with “vertical” device structure through solution‐processed transparent polymeric electrode.

All‐solid‐state flexible asymmetric supercapacitors (ASCs) are developed by utilization of graphene nanoribbon (GNR)/Co_0.85Se composites as the positive electrode, GNR/Bi₂Se₃composites as the negative electrode, and polymer‐grafted‐graphene oxide membranes as solid‐state electrolytes. Both GNR/Co_0.85Se and GNR/Bi₂Se₃composite electrodes are developed by a facile one‐step hydrothermal growth method from graphene oxide nanoribbons as the nucleation framework. The GNR/Co_0.85Se composite electrode exhibits a specific capacity of 76.4 mAh g⁻¹at a current density of 1 A g⁻¹and the GNR/Bi₂Se₃composite electrode exhibits a specific capacity of 100.2 mAh g⁻¹at a current density of 0.5 A g⁻¹. Moreover, the stretchable membrane solid‐state electrolytes exhibit superior ionic conductivity of 108.7 mS cm⁻¹. As a result, the flexible ASCs demonstrate an operating voltage of 1.6 V, an energy density of 30.9 Wh kg⁻¹at the power density of 559 W kg⁻¹, and excellent cycling stability with 89% capacitance retention after 5000 cycles. All these results demonstrate that this study provides a simple, scalable, and efficient approach to fabricate high performance flexible all‐solid‐state ASCs for energy storage.