To optimize the efficiency of mid UV LEDs with wavelengths in the range of 250 275 nm by developing in-depth understanding of the materials properties, their correlation with growth parameters, and their effect on device performance. The nature of extended defects such as threading dislocations and stacking faults that depend on lattice mismatch and polarization will be studied. Effects of strain and polarization charges on the electronic and optical performance will be studied, looking for minimization of spontaneous and piezoelectric polarization effects on the device structures. Optimization of carrier capture by the active region, and optimized contacts and light emission efficiency will be achieved by use of advanced device structures such as InAlN blocking layers. This is based on extensive prior collaborative experience within the team. Research at ASU will involve detail studies of the microstructure (TEM, XRD), the electronic properties (Electron holography in the TEM) and the optical properties (Cathodoluminescence imaging and time resolved luminescence spectroscopy); all of these carried out at the nanometer scale. A correlation between these properties will lead us to formulate the physics behind crystal growth and device performance. Crystal growth will be performed by Prof. Russell Dupuis group at Georgia Tech, the team leader. Device design, simulation, and characterization will be performed by other team members.
|Effective start/end date||9/1/10 → 8/31/13|
- DOD: Air Force (USAF): $290,449.00