Archer Paul I, Santangelo Steven A, Gamelin Daniel R
Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA.
Nano Lett. 2007 Apr;7(4):1037-43. doi: 10.1021/nl0702362. Epub 2007 Mar 23.
The defining attribute of a diluted magnetic semiconductor (DMS) is the existence of dopant-carrier magnetic exchange interactions. In this letter, we report the first direct observation of such exchange interactions in colloidal doped CdSe nanocrystals. Doped CdSe quantum dots were synthesized by thermal decomposition of (Me4N)2[Cd4(SePh)10] in the presence of TMCl2 (TM2+ = Mn2+ or Co2+) in hexadecylamine and were characterized by several analytical and spectroscopic techniques. Using magnetic circular dichroism spectroscopy, successful doping and the existence of giant excitonic Zeeman splittings in both Mn2+- and Co2+-doped wurtzite CdSe quantum dots are demonstrated unambiguously.
稀磁半导体(DMS)的决定性属性是掺杂载流子磁交换相互作用的存在。在本信函中,我们报告了在胶体掺杂的CdSe纳米晶体中首次直接观察到这种交换相互作用。通过在十六胺中存在TMCl2(TM2+ = Mn2+或Co2+)时热分解(Me4N)2[Cd4(SePh)10]合成了掺杂的CdSe量子点,并通过多种分析和光谱技术对其进行了表征。利用磁圆二色光谱,明确证明了在Mn2+和Co2+掺杂的纤锌矿CdSe量子点中成功实现了掺杂以及巨激子塞曼分裂的存在。