Effect of Dipole Rotation on Hysteresis in Methylammonium Lead Bromide
| Autor: | Chiang Fan, 范強 |
|---|---|
| Rok vydání: | 2019 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 107 Electric-field-induced dipole rotation of the intercalated organic molecules in halide perovskites has been suggested to be one controllable factor for fundamental properties and stabilities in perovskites. However, up to now, how the electric field triggers the dipole rotation of the intercalated organic molecules is still unknown. Here, we record the real-space atomic image and simultaneously probe the corresponding current-voltage (I-V) hysteresis in the methylammonium lead bromide (MAPbBr3) system using cross-sectional scanning tunneling microscopy and spectroscopy. In this work, we addressed the change of topography at specific bias intervals and anomalous I-V hysteresis with four gap-like regions as well as two unusual inflection points at forward 1.68 V and backward -0.87 V under ramp reversal scanning mode. We suppose that the dipole rotation, initiated by an electric field, concludes to two opposite surface dipole moments, creating an electronic transformation between the n-type-like and p-type-like feature. The two inflection points correspond to the critical voltage of dipole rotation. The transformation thus forms an abnormal I-V hysteresis behavior in MAPbBr3. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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