Colloidal semiconducting nanocrystals, also called colloidal quantum dots (QDs) afford efficient photoconversion from visible to infrared wavelength owing to their size-dependent optoelectronic properties. To manufacture the highly performing devices utilizing colloidal NCs, however, unreacted impurities should be removed following synthesis. As the scale of NCs synthesis increases, especially in industry, the need is heightened for large-scale purification methods that can retain the desirable optoelectronic characteristics as of as-synthesized samples. Particularly, for the use of colloidal quantum dots (QD) films for photovoltaic active layers, control over the surface during the purification needs keen attention because residual impurities or trap states introduced by inappropriate treatments during the purification are detrimental to the carrier collection efficiency of the device. In this article, we review several approaches to the purification of QDs and their successful implications for formation of the efficient photovoltaic devices. We group the purification methods according to the key property by which the separation is achieved, and discuss the scalability of each method specifically focusing on the possibility of implementing a continuous process flow that is compatible with continuous synthesis processes developed for large scale production of QDs. Finally, we present recent efforts for the highly efficient photovoltaic QD devices and discuss the importance of purification in terms of device performance.

胶体半导体纳米晶体，也称为胶体量子点（QDs），由于其尺寸相关的光电特性，可实现从可见光到红外波长的有效光转换。然而，为了利用胶体NC制造高性能器件，合成后应去除未反应的杂质。随着NCs合成规模的增加，特别是在工业中，对大规模纯化方法的需求日益增加，这种方法可以保留合成样品所需的光电特性。特别地，为了将胶体量子点（QD）膜用于光伏有源层，在纯化过程中对表面的控制需要引起高度重视，因为在纯化过程中由于不适当的处理而引入的残留杂质或捕集态对设备的载流子收集效率有害。在本文中，我们回顾了几种纯化QD的方法及其对形成高效光伏器件的成功意义。我们根据实现分离的关键特性对纯化方法进行分组，并讨论每种方法的可扩展性，重点是着眼于实现与为大规模生产量子点开发的连续合成工艺兼容的连续工艺流程的可能性。最后，