Open AccessSpectroscopy of Single Semiconductor Quantum Dots at Negative, Neutral, and Positive Charge States
Author(s) -
Regelman D.V.,
Gershoni D.,
Ehrenfreund E.,
Schoenfeld W.V.,
Petroff P.M.
Publication year - 2002
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
eISSN - 1521-396X
pISSN - 0031-8965
DOI - 10.1002/1521-396x(200204)190:2<491::aid-pssa491>3.0.co;2-g
Subject(s) - quantum dot , photoluminescence , asymmetry , quantum dot laser , exciton , charge (physics) , spectroscopy , electron , biexciton , wave function , quantum point contact , spectral line , envelope (radar) , electro absorption modulator , semiconductor , physics , condensed matter physics , molecular physics , atomic physics , optoelectronics , quantum well , quantum mechanics , laser , semiconductor laser theory , telecommunications , radar , computer science
We investigate semiconductor quantum dots by optically injecting a controlled unequal number of electrons and holes into an isolated single dot. The injected carriers form charged complexes of many carriers in the dot. Radiative electron–hole pair recombination takes place after the charged complex relaxes to its ground state. We resolve spectrally and temporally this emission and we show that while negative charging results in red shifted emission energy, compared with a neutral dot, positive charging results in blue shifted emission energy. We explain this observation in terms of the smaller volume of the hole wavefunctions compared with that of the electrons.