Linear and circular polarized photoluminescencestudies of colloidal InP/ZnS core-shell nanocrystals

摘要

The magneto-optical properties of InP/ZnS coreshell nanocrystals(NCs) were investigated, by measuring the degree of linear and circularpolarization of the photolumiscence (PL) in the presence of an externalmagnetic field and with either non-resonant or resonant polarized excitation.The linear polarized PL measurements suggest that the studied InP/ZnS NCshave a prolongated shape with elipsoid excentricity of 0.6. The resonantpolarizedexcited PL decay measurements indicated that the spin relaxationtime is much shorter than the radiative lifetime (< 70 nsec) of an exciton inInP/ZnS NCs. While, the magnetic field induced circular polarized PLmeasurements revealed a spectrosopic g-factor of the exciton of 0.55. Thedescribed measurements thus, offer the means to measure the shapedistortion and determine directly the g factors of carriers in NCs.