Realizing self-powered broadband photodetection with low detection limit in a trilayered perovskite ferroelectric

Two-dimensional perovskite ferroelectric which strongly couple ferroelectricity with semiconducting properties are promising candidates for optoelectronic applications. However, it is still a great challenge to fabricate self-powered broadband photodetectors with low detection limit. Herein, we successfully realized self-powered broadband photodetection with low detection limit by using a trilayered perovskite ferroelectric (BA)2EA2Pb3I10 (1, BA = n-butylamine, EA = ethylamine). Giving to its large spontaneous polarization (5.6 μC/cm2), 1 exhibits an open-circuit voltage of 0.25 V which provide driving force to separate carriers. Combining with its low dark current (∼10−14 A) and narrow bandgap (Eg = 1.86 eV), 1 demonstrates great potential on detecting the broadband weak lights. Thus, a prominent photodetection performance with high open-off ratio (∼105), outstanding responsivity (> 10 mA/W), and promising detectivity (>1011 Jones), as well as the low detecting limit (∼nW/cm2) among the wide wavelength from 377 nm to 637 nm was realized based on the single crystal of 1. This work demonstrates the great potential of 2D perovskite ferroelectric on self-powered broadband photodetectors.