Non-Cadmium High Performance Semiconductor Nanocrystals
D. Battaglia, S. Sunderrajan, A. Qiao
Keywords: nanocrystals, quantum dots, doped nanocrystals, nanotechnology
Abstract:Semiconductor nanocrystals are the most promising nanomaterials for several important industrial sectors, including both energy and biomedicine. The current workhorse, cadmium selenide (CdSe) based nanocrystals, suffer greatly because of the intrinsic toxicity of cadmium element. It has been a general consensus in the field that development of non-cadmium semiconductor nanocrystals with desired performance is a critical bottleneck for capturing their enormous commercialization potential. Many non-cadmium based nanocrystals have been developed. The first type is intrinsic semiconductor nanocrystals, including ZnSe (UV, purple, and blue emission), InP and CuInS (blue to red emission), and InAs (near infrared emission) ones. These intrinsic semiconductor nanocrystals, without involving any Class A element, offer high performance emission in a much broader emission window in comparison to that covered by the traditional CdSe ones. The second type is the transition metal doped semiconductor nanocrystals, D-dotsTM. The non-cadmium intrinsic semiconductor nanocrystals offer us a nice selection of host nanocrystals for producing high-performance D-dots, which further provides an extremely high absorption cross-section in comparison to traditional phosphors. Similar to the intrinsic semiconductor nanocrystals, optical emission of D-dots has been demonstrated to be extremely efficient (~80% quantum yield) and color-tunable.