We demonstrated the controllable liquid water sensitivity of polymer-encapsulated oxide-based thin-film transistors (OxTFTs). The oxide active channels of the fabricated TFTs were utilized as water-sensitive layers. The OxTFTs were encapsulated with several polymers as water controlling layers (WCLs) to investigate and optimize the water sensitivity. It was found that the surface energy and porosity of the WCL significantly affect the water-dependent electrical characteristics of the OxTFTs. By employing poly(vinylidene-trifluoroethylene) (P(VDF-TrFE)) as a WCL and annealing the chosen polymer properly, we achieved a continuous shift of the threshold voltage even after several hours of direct exposure to the liquid phase of water which is crucial for sensor properties of the OxTFTs. The device using P(VDF-TrFE) as the WCL exhibits long-term stable detection characteristics and repeatability, demonstrating its applicability as a low-cost soil moisture sensor.

中文翻译：

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聚合物封装的氧化物薄膜晶体管的可控液态水敏感性

我们证明了聚合物封装的基于氧化物的薄膜晶体管（OxTFT）的可控液体水敏感性。所制造的TFT的氧化物活性沟道被用作水敏层。OxTFT用几种聚合物作为水控制​​层（WCL）进行封装，以研究和优化水敏感性。已经发现，WCL的表面能和孔隙率显着影响OxTFT的水相关电特性。通过使用聚偏二氟乙烯-三氟乙烯（P（VDF-TrFE））作为WCL并适当地退火所选的聚合物，即使在直接暴露于水的液相中数小时后，我们也实现了阈值电压的连续偏移。对于OxTFT的传感器性能至关重要。