Abstract: The quantum dot comprises a ligand which is a copolymer comprising a first repeating unit comprising at least one or more hole transporting functional groups and a second repeating unit comprising at least one or more photocrosslinking functional groups.

Abstract: The present invention relates to a preparation method of a lithium titanium composite oxide doped with a dissimilar metal, and a lithium titanium composite oxide doped with a dissimilar metal prepared thereby, and more particularly, to a preparation method of a lithium titanium composite oxide doped with a dissimilar metal in which sizes of primary particles are finely controlled by doping a dissimilar metal and using a spray-drying method, and a lithium titanium composite oxide doped with a dissimilar metal prepared thereby. According to the present invention, the preparation method of a lithium titanium composite oxide doped with a dissimilar metal, and the lithium titanium composite oxide doped with a dissimilar metal prepared thereby allow sizes of primary particles to be finely controlled as compared with conventional lithium titanium composite oxide, and inhibit rutile titanium dioxide generation, thereby providing a battery with a high initial charge-discharge efficiency and a high rate capability.