We report the synthesis of nanocrystals with an optical feature in the THz range. To do so, we develop a new synthetic procedure for the growth of HgTe, HgSe, and HgS nanocrystals, with strong size tunability from 5 to 200 nm. This is used to tune the absorption of the nanocrystals all over the infrared range up to terahertz (from 2 to 65 μm for absorption peak and even 200 μm for cutoff wavelength). The interest for this procedure is not limited to large sizes since for small objects we demonstrate low aggregation and good shape control (i.e., spherical object) while using nonexpansive and simple mercury halogenide precursors. By integrating these nanocrystals into an electrolyte-gated transistor, we evidence a change of carrier density from p-doped to n-doped as the confinement is vanishing.

中文翻译：

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太赫兹 HgTe 纳米晶体：超越限制

我们报告了在太赫兹范围内具有光学特征的纳米晶体的合成。为此，我们开发了一种用于生长 HgTe、HgSe 和 HgS 纳米晶体的新合成程序，在 5 到 200 nm 范围内具有很强的尺寸可调性。这用于在高达太赫兹的红外范围内调整纳米晶体的吸收（从 2 到 65 μm 的吸收峰，甚至 200 μm 的截止波长）。此过程的兴趣不限于大尺寸，因为对于小物体，我们在使用非膨胀性和简单的卤化汞前体时表现出低聚集和良好的形状控制（即球形物体）。通过将这些纳米晶体集成到电解质门控晶体管中，我们证明了随着限制的消失，载流子密度从 p 掺杂变为 n 掺杂。