Material and device characterization is backbone of semiconductor research. Characterization is especially important in case of newer and less understood material systems, such as the one we deal with, III-Nitrides. Characterization forms the essential feedback path necessary in the iterative process of experiments to make high quality material and high performance devices.
Our material characterization facility includes a Philips X'pert 4 crystal X-ray diffractometer, PSIA scanning probe microscopy equipped with atomic force microscopy (AFM), Lehighton contactless resistivity mapping system, temperature-controlled Hall measurement system, photoluminescence set-up with .. specify our 3 lasers, JASCO UV-VIS-NIR photospectrometer, ellipsometry, NIKON nomarski optical microscope etc. For device characterization, our lab is equipped with Agilent 4155C semiconductor parameter analyzer, Precision impedance analyzer, Karl Suss probe station, Ando optical power meter, controller atmosphere oven etc.
We are currently investigating topics such as source of blue-green luminescence in our MOCVD grown material, cause of efficiency droop at higher currents in LEDs, polarization characteristics light emitted by an LED, junction temperature study of LEDs, performance enhancement etc.