Cu2O@Au-CsPbI3 heterostructures for plasmon hot carrier transfer enhanced optoelectronics

Plasmon hot carrier devices have tremendous potential applications in broadband photovoltaics, photodetection, photocatalysis, and intelligent optoelectronics, as they have the ability to generate hot carriers with energy lower than the optical bandgap at Schottky junctions and broaden the spectral range. However, this is mostly challenged by the lack of effective methods for the separation, migration, and extraction of plasmon hot carrier. In this work, a Cu2O@Au-CsPbI3 heterostructure was fabricated using facile low-temperature solution synthesis and spin-coating technique. The proposed heterostructure benefits from the simultaneous transfer of plasmon hot holes to Cu2O and hot electrons to CsPbI3, as well as enhanced charge separation driven by the built-in electric field at the p-n heterojunction interface. The heterostructure realizes remarkably enhanced light absorption, reduces carrier recombination, and further improves conversion efficiency. It exhibits a wide spectrum response of ultraviolet-visible-near infrared and achieves enhanced photodetection performance. The results suggest that Cu2O@Au-CsPbI3 heterostructure is a promising candidate for optoelectronic devices based on the harvesting of plasmonic hot carriers.