A systematic strategy for effectively engineering the charge extraction in inverted structured perovskite solar cells based on CH₃NH₃PbI_3−xCl_xis provided. An optimized power conversion efficiency of 20.5% is realized.

We employ alternating magnetic fields (AMF) to drive magnetic fillers actively and guide the formation and self-healing of percolation networks. Relying on AMF, we fabricate printable magnetoresistive sensors revealing an enhancement in sensitivity and figure of merit of more than one and two orders of magnitude relative to previous reports. These sensors display low noise, high resolution, and are readily processable using various printing techniques that can be applied to different substrates. The AMF-mediated self-healing has six characteristics: 100% performance recovery; repeatable healing over multiple cycles; room-temperature operation; healing in seconds; no need for manual reassembly; humidity insensitivity. It is found that the above advantages arise from the AMF-induced attraction of magnetic microparticles and the determinative oscillation that work synergistically to improve the quantity and quality of filler contacts. By virtue of these advantages, the AMF-mediated sensors are used in safety application, medical therapy, and human-machine interfaces for augmented reality.

Electronic skins (e-skins) seek to go beyond the natural human perception, e.g., by creating magnetoperception to sense and interact with omnipresent magnetic fields. However, realizing magnetoreceptive e-skin with spatially continuous sensing over large areas is challenging due to increase in power consumption with increasing sensing resolution. Here, by incorporating the giant magnetoresistance effect and electrical resistance tomography, we achieve continuous sensing of magnetic fields across an area of 120 × 120 mm² with a sensing resolution of better than 1 mm. Our approach enables magnetoreceptors with three orders of magnitude less energy consumption compared to state-of-the-art transistor-based magnetosensitive matrices. A simplified circuit configuration results in optical transparency, mechanical compliance, and vapor/liquid permeability, consequently permitting its imperceptible integration onto skins. Ultimately, these achievements pave the way for exceptional applications, including magnetoreceptive e-skin capable of undisturbed recognition of fine-grained gesture and a magnetoreceptive contact lens permitting touchless interaction.

Though mixed cation hybrid organic–inorganic perovskite materials are of promise due to the high efficiency and long-term stability of the corresponding devices, a fundamental understanding on the function of the mixed cation system is still unclear. Herein, we systematically investigate the roles of the Cs cation and Cl anion in inverted structure perovskite solar cells based on Cs_xFA_0.2MA_0.8−xPb(I_1−yCl_y)₃. For the role of Cs, we observe that an appropriate amount of Cs in the film could improve the crystal quality of the film and optimize the energy band alignment of the device, thus reducing non-radiative recombination and promoting the charge transport efficiently. The presence of Cl with a suitable concentration also possesses these functions. More importantly, the two limitations for the application of the devices, hysteresis and performance instability, could also be addressed to some extent. Thus a high power conversion efficiency of 20.31% has been realized and a universal method for constructing highly-efficient perovskite solar cells has been provided.

In this paper, silicon solar cells with Ag nanoparticles deposited on a SiO₂ spacer were studied concentrating on the influence of the surface plasmon and the antireflection film. We experimentally found that the photocurrent conversion efficiency of the solar cell decorated by random arrays of self-assembled Ag nanoparticles increases firstly and decreases afterwards with increasing spacer thickness. Further investigations on the external quantum efficiency (EQE) illustrated this trend more clearly. It was also found that the effect of the surface plasmon on light absorption dominates over that of the antireflection film at the resonance wavelength which is an important factor determining the light trapping. Moreover, surface plasmon is determined by both the Si substrate and the SiO₂ spacer. For self-assembled Ag particles on the surface of the solar cells in our experiments, appropriate spacer thickness (9-35 nm) could broaden the plasmon resonance, narrow the photocurrent suppression range, weaken the suppression amplitude and strengthen the gain at the resonance wavelength, while still providing antireflection effect.