The intrinsic low quantum yield (QY) of type II core shell quantum dots (QDs) composes the limitation for these heterostructured nanomaterials to be used in practical application. Herein, magnetic hyperthermia method is employed to intensify reaction process and facilely synthesize CdTe/CdSe heterostructured QDs with improved optical performance for the first time. The QY of the type II QDs is increased to 49% by further growing an inert ZnO layer. The type I interface between CdSe and ZnO helps confine electrons to the inner structure of the QDs, thus improving the QY. The successful preparation and performance enhancement of the CdTe/CdSe type II QDs via magnetic hyperthermia method demonstrate the great potential of this method for the preparation of other materials. Besides, the red-emission QDs are used as conversion materials in white light emitting diodes to reveal their promising application in practical illumination. (C) 2016 American Institute of Chemical Engineers