Toc

a Top-view and b cross-sectional SEM images. c XRD pattern d Steady-state absorption spectrum of FAPbBr3 MCs film. Left insets: the optical bandgap extracted from Tauc plot; right insets: PL spectrum. e PL decay of the sample excited at 376 nm, which could be well fitted by biexponential functions. f Current–voltage responses of FAPbBr3 MCs

a Current–voltage characteristics measured under back-side excitation with varying light intensity. b Responsivity and corresponding current as a function of incident light power under back-side illumination. The detector was biased at 5 V. c EQE and detectivity under different light illuminations. d Response time measured by a monochromatic source of 495 nm under back-side illumination and rise time and fall time

a Spectral-dependent photocurrent under front-side and back-side excitation at 1 mW cm−2 and a bias voltage of 5 V. b Photocurrent response measured using a series of bias voltages: 2, 3, 4, and 5 V, at an excitation of 495 nm. Normalized spectral-dependent photocurrent under different bias voltages under c back-side and d front-side excitation

a Schematic showing two-photon absorption of 800 nm light and up-conversion to 567 nm PL. b Photocurrent and c responsivity dependence at an input light intensity of 800 nm and a bias of 5 V. d Fall time measured using pulsed light of 800 nm