Arya Shaurya, Jiang Yunrui, Jung Byung Ku, Tang Yalun, Ng Tse Nga, Oh Soong Ju, Nomura Kenji, Lo Yu-Hwa
Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, California 92093, United States.
Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea.
Nano Lett. 2023 Nov 8;23(21):9943-9952. doi: 10.1021/acs.nanolett.3c02899. Epub 2023 Oct 24.
Colloidal quantum dots (CQDs) are finding increasing applications in optoelectronic devices, such as photodetectors and solar cells, because of their high material quality, unique and attractive properties, and process flexibility without the constraints of lattice match and thermal budget. However, there is no adequate device model for colloidal quantum dot heterojunctions, and the popular Shockley-Quiesser diode model does not capture the underlying physics of CQD junctions. Here, we develop a compact, easy-to-use model for CQD devices rooted in physics. We show how quantum dot properties, QD ligand binding, and the heterointerface between quantum dots and the electron transport layer (ETL) affect device behaviors. We also show that the model can be simplified to a Shockley-like equation with analytical approximate expressions for reverse saturation current, ideality factor, and quantum efficiency. Our model agrees well with the experiment and can be used to describe and optimize CQD device performance.
胶体量子点（CQD）因其高材料质量、独特且吸引人的特性以及不受晶格匹配和热预算限制的工艺灵活性，在光电器件（如光电探测器和太阳能电池）中的应用越来越广泛。然而，目前尚无适用于胶体量子点异质结的器件模型，而流行的肖克利 - 奎塞尔二极管模型无法捕捉CQD结的基本物理原理。在此，我们基于物理原理开发了一种紧凑、易于使用的CQD器件模型。我们展示了量子点特性、量子点配体结合以及量子点与电子传输层（ETL）之间的异质界面如何影响器件行为。我们还表明，该模型可以简化为一个类似肖克利的方程，具有反向饱和电流、理想因子和量子效率的解析近似表达式。我们的模型与实验结果吻合良好，可用于描述和优化CQD器件性能。
