Xu Xueli, Zhang Hui, Zhong Zhicheng, Zhang Ranran, Yin Lihua, Sun Yuping, Huang Haoliang, Lu Yalin, Lu Yi, Zhou Chun, Ma Zongwei, Shen Lei, Wang Junsong, Guo Jiandong, Sun Jirong, Sheng Zhigao
Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Science, Hefei 230031, China.
University of Science and Technology of China, Hefei, Anhui 230026, China.
ACS Appl Mater Interfaces. 2020 Jul 15;12(28):31645-31651. doi: 10.1021/acsami.0c08418. Epub 2020 Jul 1.
Rectifying semiconductor junctions are crucial to electronic devices. They convert alternating current into a direct one by allowing unidirectional charge flows. Analogous to the current-flow rectification for itinerary electrons, here, a polar rectification that is based on the localized oxygen vacancies (OVs) in a Ti/fatigued-SrTiO (fSTO) Schottky junction is first demonstrated. The fSTO with OVs is produced by an electrodegradation process. The different movabilities of localized OVs and itinerary electrons in the fSTO yield a unidirectional electric polarization at the interface of the junction under the coaction of external and built-in electric fields. Moreover, the fSTO displays a pre-ferroelectric state located between paraelectric and ferroelectric phases. The pre-ferroelectric state has three sub-states and can be easily driven into a ferroelectric state by an external electric field. These observations open up opportunities for potential polar devices and may underpin many useful polar-triggered electronic phenomena.
