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The recent strong interest in obtaining devices with high temperature functioning, high switching speed and high power performances has focused research attention on new wide band gap materials. Among them, gallium nitride (GaN) has gained attention due to its high band gap value (~3.4 eV at room temperature) that makes it goes intrinsic at much higher temperature than Si, but also due to its high saturation velocity (higher than for SiC) and high critical electric field allowing to reach larger breakdown voltage values. For the last few years, it has already found applications in topics such as optoelectronic devices, blue to green light emitting diodes (LEDs), laser diodes (LDs), detectors and high electron mobility transistors (HEMTs).

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Dr.N.Nanda Kumar Reddy presently working as Assistant Professor in Department of Physics, Madanapalle Institute of Technology and Science, Angallu, Madanapalle, Chtittoor(Dist.), A.P, India. He received his Ph.D from S.V.University, Tirupati, A.P,India.He Published 12 referred international journals and presented 13 research papers in conferences.

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