1.中国科学技术大学 纳米技术与纳米仿生学院;2.中国科学院苏州纳米技术与纳米仿生研究所 纳米器件及其应用重点实验室
1.The School of Nano-Tech and Nano-Bionics,University of Science and Technology of China;2.The Key Lab of Nanodevices and Applications,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences
本文提出了采用金属有机化学气相沉积(MOCVD)生长无Ga且应力平衡的InAsP/InAsSb超晶格并探索了其作为红外吸收材料的可行性。首先采用k.p理论计算了InAsP/InAsSb超晶格的带隙,发现其波长调节范围可以从中波红外到长波红外。然后通过MOCVD技术在InAs衬底上生长了InAs0.8P0.2/InAs0.7Sb0.3超晶格。XRD测试结果表明InAs衬底峰与超晶格零级卫星峰的失配仅61弧秒,即基本实现应力平衡；AFM测试材料表面形貌显示5×5 μm2范围内均方根粗糙度为0.4 nm；低温PL光谱显示较强的发光,峰位于3.3 μm的中波红外波段,接近设计值。这些结果表明采用MOCVD生长应力平衡的InAsP/InAsSb超晶格作为红外探测材料具有较好的可行性和实用性。
“Ga free” strain-balanced InAsP/InAsSb superlattices grown on InAs substrate by Metal Organic Chemical Vapor Deposition(MOCVD)was proposed and implemented to explore its feasibility as an infrared absorption material. First, the band gaps of InAsP/InAsSb superlattices were calculated by k.p method and it was found that their cut-off wavelengths cover mid-wavelength infrared to long wave infrared region. Then InAs0.8P0.2/InAs0.7Sb0.3superlattices was chosen and grown on InAs substrate by MOCVD. XRD measurement shows that the lattice mismatch between the InAs substrate peak and 0th order satellite peak of superlattices is only 61 arcsec, indicating strain balance condition is achieved. AFM test for surface morphology shows its root mean square roughness is only 0.4 nm for 5×5 μm2 regions. The low-temperature PL spectra shows strong superlattice emission with peak located around 3.3 μm, which is closed to the design value. All the results indicate the feasibility and practicality of strain balanced InAsP/InAsSb superlattices grown by MOCVD for infrared detection.