Photoluminescence properties of InP/GaP/ZnS core/shell/shell colloidal quantum dots treated with halogen acids

InP quantum dots (QDs) with low toxicity are considered to be the most promising materials. However, the oxidation problem of In and P has become to the major factor affecting the optical properties of InP QDs. In this work, the effect of luminescence properties of InP/GaP/ZnS QDs with halogen acid treatment have been studied. The results show that HF and HCl are beneficial to improve the optical properties of QDs, HBr especially HI are not conductive to promote the photoluminescence quantum yield (PL QY) of QDs. HF and HCl can etch the oxidative layer effectively, the F− and Cl− can also passivate the surface indium dangling bonds in the form of atomic ligands. The proposed model of charge carrier recombination show that the PL QY improved significantly after HA treatment attributed to the recombination of electron-hole pairs through radiative pathways mainly from the conduction band and valence band. The InP QDs with HF treatment has the best luminescence properties with high PL QY of 96%, offering great potential for advanced optoelectronic devices.