Broadband photodetection of intense lasers via exciton-enhanced high-order multiphoton-absorption optoelectronics in 2D hybrid perovskite.

Broadband photodetection, especially for the high-intensity pulsed lasers, has garnered increasing interest in photophysics and applied sciences driven by the development of pulsed lasers. However, direct broadband photodetection of high-intensity pulsed lasers, with precisely capturing their spatiotemporal properties, has been hampered by low saturation intensity or damage threshold of traditional optoelectronic materials. Here, we demonstrate that strategic enhancement of excitonic effects in two-dimensional (2D) layered hybrid perovskite can enable robust high-order multiphoton absorption (MPA) optoelectronics with achieving strong four-photon absorption (4PA) and five-photon absorption (5PA) nonlinearities as well as efficient electronic properties simultaneously. This effectively overcomes the limitations of mainstream photodetectors. Our approach facilitates direct photodetection and high-precision imaging of high-intensity femtosecond lasers (21.5 GW/cm) across a broad wavelength range of 800 to 2300 nanometer. These results offer valuable insights into advancing high-order nonlinearity-based optoelectronics and provide practical solutions for direct measurement tools of intensive lasers, filling the blank of high-precision characterization of intense-field laser phenomena.