Institute of Microwaves and Photonics, School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom.
Nano Lett. 2013 May 8;13(5):2047-52. doi: 10.1021/nl4003014. Epub 2013 Apr 29.
Size tunability of the optical properties and inexpensive synthesis make semiconductor nanocrystals one of the most promising and versatile building blocks for many modern applications such as lasers, single-electron transistors, solar cells, and biological labels. The performance of these nanocrystal-based devices is however compromised by efficient trapping of the charge carriers. This process exhibits different features depending on the nanocrystal material, surface termination, size, and trap location, leading to the assumption that different mechanisms are at play in each situation. Here we revolutionize this fragmented picture and provide a unified interpretation of trapping dynamics in semiconductor nanocrystals by identifying the origins of this so far elusive detrimental process. Our findings pave the way for a general suppression strategy, applicable to any system, which can lead to a simultaneous efficiency enhancement in all nanocrystal-based technologies.
尺寸可调的光学性质和廉价的合成方法使得半导体纳米晶体成为最有前途和多功能的构建块之一，可用于许多现代应用，如激光、单电子晶体管、太阳能电池和生物标记。然而，这些基于纳米晶体的器件的性能受到电荷载流子有效捕获的影响。这个过程的表现因纳米晶体材料、表面终止、尺寸和陷阱位置的不同而有所不同，这导致人们假设在每种情况下都有不同的机制在起作用。在这里，我们通过确定这个迄今为止难以捉摸的有害过程的起源，彻底改变了这种分散的局面，并为半导体纳米晶体中的俘获动力学提供了统一的解释。我们的发现为通用的抑制策略铺平了道路，适用于任何系统，这可以同时提高所有基于纳米晶体的技术的效率。
