Carbon-based fully printable self-powered ultraviolet perovskite photodetector: Manganese-assisted electron transfer and enhanced photocurrent

In this work, we improved the photocurrent of self-powered ultraviolet photodetector via doping manganese in CsPbCl3 perovskite nanocrystals light harvester. The doped manganese in nanocrystals has the following three features to assist electron transfer from CsPbCl3 nanocrystals to titanium dioxide: (i) the fast exciton-to-manganese energy transfer process benefits for competing electrons with perovskite exciton recombination, (ii) the charge carrier lifetime is very long for manganese d-states due to its spin and orbital forbidden transition, and (iii) the electrons can effectively transfer to the titanium dioxide layer from 4T1 of manganese d-states due to the smaller energy barrier. Based on the above, the self-powered photocurrent density of photodetectors has nearly twice enhancement from 0.08 mA·cm−2 to 0.14 mA·cm−2 and a high responsivity up to 7.3 mA·W−1 was achieved at 340 nm.