Seeded Growth of Highly Luminescent\nCdSe/CdS Nanoheterostructures with\nRod and Tetrapod Morphologies

We have demonstrated that seeded growth of nanocrystals offers a convenient way to design nanoheterostructures with complex shapes and\nmorphologies by changing the crystalline structure of the seed. By using CdSe nanocrystals with wurtzite and zinc blende structure as seeds\nfor growth of CdS nanorods, we synthesized CdSe/CdS heterostructure nanorods and nanotetrapods, respectively. Both of these structures\nshowed excellent luminescent properties, combining high photoluminescence efficiency (∼80 and ∼50% for nanorods and nanotetrapods,\ncorrespondingly), giant extinction coefficients (∼2 × 10<sup>7</sup> and ∼1.5 × 10<sup>8</sup> M<sup>-1</sup> cm<sup>-1</sup> at 350 nm for nanorods and nanotetrapods, correspondingly),\nand efficient energy transfer from the CdS arms into the emitting CdSe core.