用于中波红外探测的InAsP/InAsSb超晶格的MOCVD生长和表征

Growth and characterization of InAsP/InAsSb superlattices by Metal Organic Chemical Vapor Deposition for mid-wavelength detection

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InAs_(0.8)P_(0.2)/InAs_(0.7)Sb_(0.3)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",即基本实现应力平衡;AFM测试材料表面形貌显示5μm×5μm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3.3μm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 wavelength cover mid-wavelength infrared to long wave infrared region.Then,InAs_(0.8)P_(0.2)/InAs_(0.7)Sb_(0.3)superlattices were chosen and grown on InAs substrate by MOCVD.XRD measurement shows that the lattice mismatches between the InAs substrate peak and 0thorder satellite peak of superlattices is only 61",indicating strain balance condition is achieved.AFM test for surface morphology shows its root mean square roughness is only 0.4 nm for 5×5μm^(2) regions.The low-temperature PL spectra shows strong superlattice emission with peak located around 3.3μm,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.