| 总结: | We report the generation of neutral, negatively charged and positively charged excitons in the same single InAs quantum dot in a controlled manner. The control parameters of the respective excitons are a vertical electric field, applied to a capacitor-like structure in which the quantum dots are embedded, and optical pump power. We have already established that Coulomb blockade can be exploited to control the charge of excitons containing one hole, the neutral exciton, X0, and the singly negatively charged exciton, X 1-. We extend this concept to excitons containing 2 holes, the biexciton, 2X0, and significantly the singly positively charged exciton, X1+. We support these assignments with a Coulomb blockade (CB) model. The emission from X1- is always redshifted from X 0, but surprisingly we observe blue- as well as redshifts for X 1+ from X0. © 2005 American Institute of Physics.
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