Department of Materials Science and Centre for Advanced Materials, Indian Association for the Cultivation of Science, Jadavpur 700032, India.
J Am Chem Soc. 2011 Feb 2;133(4):1007-1015. doi: 10.1021/ja1089809.
Cu-doped inorganic semiconductors with concomitant optical properties have garnered enormous research interest in the last two decades. However, uncertainties over the origin of Cu emission, its oxidation state, resemblance with trap state emission, position of Cu d-state, emission spectral width, and moreover understanding of the doping mechanism restricted the wide development of the synthetic methodology for high-quality Cu-doped nanocrystals. It has been shown recently that the emission from Cu-doped semiconductor nanocrystals can span over a wide spectral window and could be a potential color tunable dispersed nanocrystal emitter. Herein, we report the size and composition of variable Cu-doped ZnS/Zn(1−x)Cd(x)S zinc-blende (ZB) surface alloyed nanocrystals with intense, stable, and tunable emission covering the blue to red end of the visible spectrum. Further, the Cu dopant emission is distinguished from trap state emission, and the composition variable spectral broadening has been justified on the account of a different environment around the Cu ions in the host lattice. Whereas some findings are in agreement with past reports, several new physical insights presented here would help the community for an in-depth mechanistic study on Cu doping. Moreover, these doped nanocrystal emitters can be a promising candidate for application ranging from optoelectronics to bio-labeling.
在过去的二十年中，具有伴随光学性质的铜掺杂无机半导体引起了极大的研究兴趣。然而，由于铜发射的起源、氧化态、与陷阱态发射的相似性、铜 d 态的位置、发射光谱宽度的不确定性，以及对掺杂机制的理解有限，限制了高质量铜掺杂纳米晶体的合成方法的广泛发展。最近已经表明，铜掺杂半导体纳米晶体的发射可以覆盖很宽的光谱窗口，并且可能是一种潜在的可调谐颜色的分散纳米晶体发射器。在此，我们报告了具有强、稳定和可调发射的不同尺寸和组成的铜掺杂 ZnS/Zn(1-x)Cd(x)S 闪锌矿 (ZB) 表面合金纳米晶体，发射覆盖了从蓝色到红色的可见光谱。此外，铜掺杂剂的发射与陷阱态发射区分开来，并且根据宿主晶格中铜离子周围不同的环境，对组成可变的光谱展宽进行了合理的解释。虽然一些发现与过去的报告一致，但这里提出的一些新的物理见解将有助于深入研究铜掺杂的机制。此外，这些掺杂纳米晶体发射器可以作为从光电到生物标记等应用的有前途的候选材料。
