Selective formation of GaN-based nanorod heterostructures on soda-lime glass substratesby a local heating method

Abstract

We report on the fabrication of high-quality GaN on soda-lime glass substrates, heretoforeprecluded by both the intolerance of soda-lime glass to the high temperatures requiredfor III-nitride growth and the lack of an epitaxial relationship with amorphousglass. The difficulties were circumvented by heteroepitaxial coating of GaN onZnO nanorods via a local microheating method. Metal-organic chemical vapordeposition of ZnO nanorods and GaN layers using the microheater arrays producedhigh-quality GaN/ZnO coaxial nanorod heterostructures at only the desired regions onthe soda-lime glass substrates. High-resolution transmission electron microscopyexamination of the coaxial nanorod heterostructures indicated the formation ofan abrupt, semicoherent interface. Photoluminescence and cathodoluminescencespectroscopy was also applied to confirm the high optical quality of the coaxial nanorodheterostructures. Mg-doped GaN/ZnO coaxial nanorod heterostructure arrays, whoseGaN shell layers were grown with various different magnesocene flow rates, werefurther investigated by using photoluminescence spectroscopy for the p-type dopingcharacteristics. The suggested method for fabrication of III-nitrides on glass substratessignifies potentials for low-cost and large-size optoelectronic device applications.