We summarize the progress in organic–inorganic hybrid and all-inorganic wide- E _g perovskite solar cells. Key challenges and effective strategies are discussed, followed by applications in tandems. We outline perspectives to design superior devices.

Solution-processed materials, including halide perovskites and newly discovered MXenes, are emerging as promising candidates for next-generation optoelectronic devices. Here, large-scale image sensor arrays (1250 pixels) based on a MXene/perovskite/MXene structure are demonstrated by utilizing top-down techniques, i.e. spin-coating and laser-scribing. The work allows processing perovskite and MXene materials into sub-millimeter photodetector arrays on a large scale with potential for further down-scaling of the device dimensions. The favorable energy level alignment and resonance enhancement of such materials enable efficient charge transfer and detection up to the near infrared region. A high responsivity of 84.77 A W⁻¹, a high specific detectivity of 3.22 × 10¹² Jones, and a large linear dynamic range (LDR) up to 82 dB in a broadband wavelength range from visible to near-infrared are achieved. In addition, the device shows an excellent image-capture capability under near infrared illumination. Given the tunability and compatibility with complementary metal–oxide–semiconductors (CMOS), the method potentially promotes the development of low-cost, high-performance, and large format photodetector arrays.

The improved performance for KI incorporated perovskite solar cells are clarified from the point view of grain boundry and interface passivation.