Tuning phase transitions in FeSe thin flakes by field-effect transistor with solid ion conductor as the gate dielectric

作者：Bin Lei, N. Z. Wang, Chao Shang, Fanbao Meng, L. K. Ma, X. G. Luo, Tao Wu, Zeyuan Sun, Yu Wang, Zheng Jiang, B. Mao, Zhi Liu, Yijun Yu, Yifei Zhang, Xianhui Chen · 发表于：Physical review. B./Physical review. B · 年份：2017 · DOI：10.1103/physrevb.95.020503 · 被引用次数：100 · 研究领域：Iron-based superconductors research、Physics of Superconductivity and Magnetism、Magnetic and transport properties of perovskites and related materials

We have developed a field-effect transistor (FET) device using a solid ion conductor (SIC) as the gate dielectric, which can tune the carrier density of FeSe by driving lithium ions in and out of the FeSe thin flakes and consequently control the physical properties and phase transitions. A dome-shaped superconducting phase diagram was mapped out with increasing Li content, with ${T}_{c}\ensuremath{\sim}46.6$ K for optimal doping, and an insulating phase was reached at the extremely overdoped regime. Our study suggests that, by using a solid ion conductor as the gate dielectric, the SIC-FET device is able to induce much higher carrier doping in the bulk, suit many surface-sensitive experimental probes, and stabilize structural phases that are inaccessible in ordinary conditions.