Development of lasing QD nanostructures with highly luminescent emission spectra based on In1-xScxP QDs prepared via tetradecanoic acid assisted wet chemical route for laser diode applications

摘要

New lasing QD nanostructures with intense emission spectra based on In1-xScxP QD crystals were prepared via tetradecanoic acid assisted wet chemical route. The doping of Sc in the In1-xScxP QD crystals instigated increasing of lattice constants and crystallites size of their zinc blende cubic crystals. The images of TEM scrutinized that the formed nanocrystal were highly monodisperse particles and their mean diameter increased from 2.8 nm to 5.9 nm. The images of HRTEM reflected that that the d-spacing increased from 0.583 nm to 0.62 nm upon the increasing of Sc dopant amount in the InP crystals. The spectrum of optical absorption curves showed a displacement toward the long wavelength as the amount of Sc dopants increased in the InP crystals, comprising the decrease of the optical gaps from 2.04 eV to 1.73 eV. The insert of Sc-dopant in the InP QDs inspected a shift of the emission spectra to red light, confirming the decrease of the optical and gap. Moreover, the inclusion of Sc atoms in the In atom cites of the InP QDs gave rise to an enlargement of the luminescent intensity of the emitted lights from these nanocrystals by 9 times. It is found a remarkable decreasing of the Stokes shift reached to 97 % was achieved, implying the surface defects were passivized. The increase of the Sc-dopant in the InP QD crystal resulted in a decreasing of the emission band width by 5 times. The quantum yields changed from 12 % to 78 % due the increasing of the amount of Sc dopant in the InP QD crystals. These outstanding behaviors make these sorts of novel QDs to be served as efficient lasing nanomaterials for the development of laser diode.