We fabricated a ligand-free lead selenide (PbSe) colloidal quantum dot (CQD) film and probed its electrical properties using a field-effect transistor (FET) at low temperature. The contribution of the ionic conduction to the electrical properties in the PbSe CQD film became significant after ligand removal using ammonium sulfide [(NH₄)₂S], evidenced by temperature-dependent FET mobility, threshold voltage, and current hysteresis depending on gate scan direction. The enhanced FET mobility and increased carrier concentration at a lower temperature are attributed to reduced ionic conduction, suppressing the gate electric field screening at the PbSe/SiO₂ interface.

我们制造了无配体硒化铅（PbSe）胶体量子点（CQD）膜，并在低温下使用场效应晶体管（FET）探测了其电性能。在使用硫化铵[（NH ₄）₂ S]去除配体后，离子传导对PbSe CQD膜中电性能的贡献变得显着，这取决于温度依赖的FET迁移率，阈值电压和取决于门扫描的电流滞后方向。较低的温度下增强的FET迁移率和增加的载流子浓度归因于离子传导的减少，从而抑制了PbSe / SiO ₂界面处的栅电场屏蔽。