Highly luminescent cadmium telluride (CdTe) nanocrystals were synthesized usingLi2[Cd4(SPh)10] as a reactive Cd cluster compound at relatively low temperature, making it a safe precursorfor the large scale synthesis of CdTe nanocrystals. Transmission electron microscopy(TEM) showed that the shape of the CdTe nanocrystals changes from nanorods tobranched structures with increasing reaction time. The nanocrystals show highluminescent quantum yields up to 37% for CdTe branched nanostructures, and ashigh as 52% for CdTe/CdS core–shell heterostructures. CdTe/CdS nanocrystalswere used to make light-emitting diodes in combination with organic layers forelectron and hole injection. The devices show a maximum luminance efficiency of0.35 cd A−1.