  We report on growth and characterization of individual InAsP/GaInP quantum
dots with variable nominal As molar fraction. Magneto-photoluminescence
experiments reveal QD emission in a wide range from 1.3 to 1.8 eV confirming
incorporation of As into quantum dots. Transmission electron microscopy reveals
a core-cap structure of InAsP quantum dots with an InAs-rich core capped by an
InP-rich layer. Inside the core, an As molar fraction up to x=0.12 is observed.
The heavy hole g-factor is found to be strongly dependent on As molar fraction,
while the electron g-factor is close to the InP values. This suggests type-II
carrier confinement in the studied InAsP dots with holes (electrons) localized
in the core (cap) region. Finally, dynamic nuclear polarization is observed
which allows for further insight into structural properties using nuclear
magnetic resonance.
