Liu William K, Whitaker Kelly M, Smith Alyssa L, Kittilstved Kevin R, Robinson Bruce H, Gamelin Daniel R
Department of Chemistry and Center for Nanotechnology, University of Washington, Seattle, Washington 98195, USA.
Phys Rev Lett. 2007 May 4;98(18):186804. doi: 10.1103/PhysRevLett.98.186804. Epub 2007 May 2.
Conduction band electrons in colloidal ZnO quantum dots have been prepared photochemically and examined by electron paramagnetic resonance spectroscopy. Nanocrystals of 4.6 nm diameter containing single S-shell conduction band electrons have g()=1.962 and a room-temperature ensemble spin-dephasing time of T(2)()=25 ns, as determined from linewidth analysis. Increasing the electron population leads to increased g() and decreased T(2)(), both associated with formation of P-shell configurations. A clear relationship between T(2)(*) and hyperfine coupling with 67Zn(I=5/2) is observed.
通过光化学方法制备了胶体ZnO量子点中的导带电子，并利用电子顺磁共振光谱对其进行了研究。直径为4.6 nm且包含单个S壳层导带电子的纳米晶体，其g()=1.962，根据线宽分析确定室温下的系综自旋退相时间T(2)() = 25 ns。电子数量增加会导致g()增大且T(2)()减小，这两者都与P壳层构型的形成有关。观察到T(2)(*)与67Zn（I = 5/2）的超精细耦合之间存在明确的关系。
