Smith Charles, Binks David
School of Physics and Astronomy and Photon Science Institute, University of Manchester, Manchester M13 9PL, UK.
Nanomaterials (Basel). 2013 Dec 24;4(1):19-45. doi: 10.3390/nano4010019.
In a conventional solar cell, the energy of an absorbed photon in excess of the band gap is rapidly lost as heat, and this is one of the main reasons that the theoretical efficiency is limited to ~33%. However, an alternative process, multiple exciton generation (MEG), can occur in colloidal quantum dots. Here, some or all of the excess energy is instead used to promote one or more additional electrons to the conduction band, potentially increasing the photocurrent of a solar cell and thereby its output efficiency. This review will describe the development of this field over the decade since the first experimental demonstration of multiple exciton generation, including the controversies over experimental artefacts, comparison with similar effects in bulk materials, and the underlying mechanisms. We will also describe the current state-of-the-art and outline promising directions for further development.
在传统太阳能电池中，被吸收光子超过带隙的能量会迅速以热量形式损失，这是理论效率被限制在约33%的主要原因之一。然而，一种替代过程，即多激子产生（MEG），可在胶体量子点中发生。在此过程中，部分或全部多余能量转而用于将一个或多个额外电子激发到导带，这有可能增加太阳能电池的光电流，进而提高其输出效率。本综述将描述自首次实验证明多激子产生以来这一领域十年间的发展情况，包括关于实验假象的争议、与块体材料中类似效应的比较以及潜在机制。我们还将描述当前的技术水平，并概述进一步发展的前景方向。
