Large-diameter, lithium-free ZnO single-crystal substrates of high crystalline quality will enable development and
commercialization of high-performance ZnO-based semiconductor devices, such as UV and visible light emitting diodes
(LEDs), UV laser diodes and solar-blind UV detectors for variety of applications. We have recently developed a novel
crystal growth technique for producing lithium-free ZnO single crystal boules of 1 inch in diameter. We also fabricated
ZnO single crystal wafers in sizes up to 1 inch in diameter. Chemical purity, crystalline defects, and electrical resistivity
of ZnO single crystals were analyzed. Results from crystal growth and material characterization are presented and
discussed. Our research results suggest that the novel crystal growth technique is a viable production technique for
producing ZnO single crystals and substrates for semiconductor device applications.