生长在图形化蓝宝石衬底上的GaN薄膜光学性质研究

Optical Properties of GaN Films Grown on Patterned Sapphire Substrates

图形化蓝宝石衬底(PSS)技术作为提高LED发光效率的方法之一,一直备受关注。研究了PSS上生长的GaN薄膜的表面形貌、吸收光谱、红外光谱、拉曼散射(Raman)和太赫兹光谱等,并与常规蓝宝石衬底上的GaN外延薄膜进行对比。结果表明,PSS上生长的GaN外延薄膜的表面形貌、光提取效率(LEE)得到明显改善。此研究成果对进一步提高GaN基短波(蓝/紫光)发光二极管(LED)的发光效率具有一定的借鉴意义,为进一步拓展PSS器件的太赫兹响应提供了依据。

Patterned sapphire substrate(PSS)technology has been attracting much attention as one of the methods to improve the luminescence efficiency of LEDs.The surface morphology,absorption spectra,infrared spectra,Raman scattering and terahertz spectra of GaN films grown on PSS are investigated and compared with GaN epitaxial films on conventional sapphire substrates.The results show that the surface morphology and light extraction efficiency(LEE)of the GaN epitaxial films grown on PSS have been significantly improved.The research result has certain reference significance for further improving the luminous efficiency of GaN-based short-wave(blue/violet)LEDs,and provides a basis for further expanding the terahertz response of PSS devices.