The major objectives of the effort include the following: Comprehensive study of the mechanisms of carriers' TM ions energy transfer due to carrier impact and recombination in bulk and quantum confined structures. Design, fabrication, and characterization of TM doped II-VI structures for electroluminescence and laser studies. Comprehensive studies and optimization of lasing characteristics of electrically pumped TM-doped II-VI structures.
Intellectual merit: For realization of electrically pumped lasers based on transition metal (TM) doped II-VI structures two conditions should be satisfied: (i) sustainable excitation of the host by electrical current; and (ii) effective energy transfer from the host to the mid-IR lasing TM impurity. The feasibility of the first condition is supported by development of II-VI LED sources with a lifetime exceeding 10,000 hours. The second condition can be achieved either via carrier impact energy transfer or via recombination processes. We envision that understanding and optimization of the mechanisms of carrier TM ions energy transfer will enable significant improvement in the efficiency of energy transfer for carrier impact mechanisms, and especially for TM ions excitation via recombination processes in bulk p-n junctions and in quantum confined structures.
Broader impacts: The workforce development will involve (i) incorporation of findings into four courses taught to two campuses of the University of Alabama System, (ii) graduate student training, and (iii) undergraduate student research through REU site. In addition, the innovative approaches to be investigated will lead to ground-breaking advances for low-cost electrically pumped broadly tunable mid-IR laser sources which will impact medical, environmental, scientific, and counter-terrorism applications.
