Subcategory: Materials Science
Janay Frazier - Norfolk State University
Co-Author(s): Gary Harris and James Griffin, Howard University, Washington, DC
Ultraviolet light emitting diodes (UV LEDs) have been used in a variety of applications and as a result are becoming cheaper to fabricate. LED products have reached 12 watts at 914 amperes. Initial UV LEDs were fabricated with GaN films grown on sapphire substrates. The main disadvantage of this fabrication technology is the difficulty in growing high quality GaN films on sapphire because of the large lattice mismatch. Diamond has a wide energy band gap of 5.47 eV; which makes it attractive for opto-electrical applications. Its high thermal conductivity makes it an excellent material for UV LED fabrication. In this work diamond UV LEDs were fabricated by growing high-quality diamond films on silicon and silicon carbide (SiC) substrates by hot filament chemical vapor deposition (HFCVD). Methane was used as the carbon source gas with solid source boron used as the p-type dopant and nitrogen used as the n-type dopant. Hall measurements confirmed a hole concentration of approximately 3x1019cm-3, a carrier mobility of 73 cm2/V-sec, and a resistivity of 5X10-3Ω -cm.
Funder Acknowledgement(s): I would like to thank my mentor Mr. James Griffin and my Principal Investigator Dr. Gary Harris. I also give my utmost gratitude to the National Nanotechnology Infrastructure Network (NNIN). This research was supported by the National Science Foundation under Grant No. ECCS-0335765.
Faculty Advisor: James Griffin,