Strain relaxation and optical properties of etched In0.19Ga0.81N nanorod arrays on the GaN template

• 来源期刊: 中国物理B（英文版）
• 关键词: InGaN/GaN nanorod arrays photoliminescence strain relaxation recombination
• 年，卷（期）: 2012,（8）
• 页码范围: 511-516
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/21/8/087802

摘要

InGaN/GaN epilayers,which are grown on sapphire substrates by the metal-organic chemical-vapour deposition (MOCVD) method,are formed into nanorod arrays using inductively coupled plasma etching via self-assembled Ni nanomasks.The formation of nanorod arrays eliminates the tilt of the InGaN (0002) crystallographic plane with respect to its GaN bulk layer.Photoluninescence results show an apparent S-shaped dependence on temperature.The light extraction efficiency and intensity of photoluminescence emission at low temperature of less than 30 K for the nanorod arrays are enhanced by the large surface area,which increases the quenching effect because of the high density of surface states for the temperature above 30 K.Additionally,a red-shift for the InGaN/GaN nanorod arrays is observed due to the strain relaxation,which is confirmed by reciprocal space mapping measurements.