Abstract
We fabricate photodetectors based on solution-processed single CH3NH3PbBr3 microcrystals (MCs) and map the two-photon absorption (TPA) excited photocurrent (PC) with spatial resolution of 1 μm. We find that the charge carrier transport length in the MCs depends on the applied electric field, and increases from 5.7 μm for 0.02 V bias (dominated by carrier diffusion) to 23.2 μm for 2 V bias (dominated by carrier drift). Furthermore, PC shows strong spatial variations. Combining the PC mapping results with time-resolved photoluminescence microscopy, we demonstrate that the spatial distribution of PC mainly originates from the inhomogeneous distribution of trap-states across perovskite MCs. This suggests that there is still large margin for improvement of perovskite single crystal devices by better controlling of the traps.
Original language | English |
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Pages (from-to) | 5017-5022 |
Number of pages | 6 |
Journal | Journal of Physical Chemistry Letters |
Volume | 9 |
Issue number | 17 |
DOIs | |
State | Published - 6 Sep 2018 |
Externally published | Yes |