p-Type AgAuSe Quantum Dots

作者：Zhiyong Tang, Zhixuan Wang, Hongchao Yang, Zhiwei Ma, Yejun Zhang, Jiang Jiang, Qiangbin Wang · 发表于：Journal of the American Chemical Society · 年份：2024 · DOI：10.1021/jacs.4c10691 · 被引用次数：12 · 研究领域：Quantum Dots Synthesis And Properties、Chalcogenide Semiconductor Thin Films、Copper-based nanomaterials and applications

Control over the carrier type of semiconductor quantum dots (QDs) is pivotal for their optoelectronic device applications, and it remains a nontrivial and challenging task. Herein, a facile doping strategy via K impurity exchange is proposed to convert the NIR n-type toxic heavy-metal-free AgAuSe (AAS) QDs to p-type. When the dopant reaches saturation at approximately 22.2%, the Femi level shifts down to near the valence band, with the p-type carrier characteristics confirmed through photoluminescence, X-ray photoelectron spectroscopy, and ultraviolet photoelectron spectroscopy analysis. First-principles calculations reveal that K impurities preferentially occupy interstitial positions and form complex defects when combined with the abundant cationic vacancy in AAS caused by the high mobility of Ag, thereby functioning as a shallow acceptor to enhance p-type conductivity. A p–n homojunction based on AAS QDs has been fabricated and served as the active layer in a photodiode device, which demonstrates an excellent room-temperature detectivity of up to 2.29 × 10 13 Jones and an outstanding linear dynamic range of over 103 dB. This study provides guidance for future design of the p–n homojunction using the toxic-metal-free Ag-based QDs and further unleashes their potential in advanced optoelectronic device applications.