In this study, we investigated the gate voltage dependence of $T_{\mathrm c}$ in electrochemically etched FeSe films with an electric-double layer transistor structure. The $T_{\mathrm c}^{\mathrm {zero}}$ value of the etched FeSe films with a lower gate voltage ($V_{\mathrm g}$ = 2.5 and 3.3 V) reaches 46 K, which is the highest value among almost all reported values from the resistivity measurements except for the data by Ge et al. This enhanced $T_{\mathrm c}$ remains unchanged even after the discharge process, unlike the results for electrostatic doping without an etching process. Our results suggest that the origin of the increase in $T_{\mathrm c}$ is not electrostatic doping but rather the electrochemical reaction at the surface of an etched films.

中文翻译：

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电化学蚀刻的 FeSe/LaAlO3 薄膜中超导转变温度的提高

在这项研究中，我们研究了具有双电层晶体管结构的电化学蚀刻 FeSe 薄膜中 $T_{\mathrm c}$ 的栅极电压依赖性。具有较低栅极电压（$V_{\mathrm g}$ = 2.5 和 3.3 V）的蚀刻 FeSe 薄膜的 $T_{\mathrm c}^{\mathrm {zero}}$ 值达到 46 K，这是除了 Ge 等人的数据外，几乎所有报告的电阻率测量值中的最高值。这种增强的 $T_{\mathrm c}$ 即使在放电过程之后也保持不变，这与没有蚀刻过程的静电掺杂结果不同。我们的结果表明，$T_{\mathrm c}$ 增加的原因不是静电掺杂，而是蚀刻薄膜表面的电化学反应。