High Resolution Mapping of Two-Photon Excited Photocurrent in Perovskite Microplate Photodetector

Summary, in English

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.

• Author: Bin Yang; Junsheng Chen; Qi Shi; Zhengjun Wang; Marina Gerhard; Alexander Dobrovolsky; Ivan G. Scheblykin; Khadga Jung Karki; Keli Han; Tõnu Pullerits
• Department/s: NanoLund: Centre for Nanoscience; Chemical Physics
• Publishing year: 2018-09-06
• Language: English
• Pages: 5017-5022
• Publication/Series: Journal of Physical Chemistry Letters
• Volume: 9
• Issue: 17
• Links: http://dx.doi.org/10.1021/acs.jpclett.8b02250
• Document type: Journal article
• Publisher: The American Chemical Society (ACS)
• Topic: Physical Chemistry (including Surface- and Colloid Chemistry); Condensed Matter Physics (including Material Physics, Nano Physics)
• Status: Published
• ISBN/ISSN/Other: ISSN: 1948-7185