Fabrication And Characterization Of Antimony-based Interband Cascade Lasers And Materials

The lasers and detectors of mid-infrared spectral range have a wide range of applications,particularly in defense,medical and telecommunications areas.There are some different ways to obtain infrared light.Antimonide semiconductor laser with active region of In As/Ga Sb type II superlattice is the most popular to obtain the mid-infrared light at present.The devlopment process on antimonide semiconductor laser is restricted on material grown,the lattice mismatch,defect density,stress and so on are inevitable.Based on the above background,this paper studied the Ga Sb substrate films epitaxially grown on Ga Sb and In As / Ga Sb superlattice structure.Physical properties characterization of epitaxially grown on Ga Sb,thin film layer doping,passivation and interface control superlattice structure are studied in detail.Infrared optoelectronic devices based on III–V compound semiconductor materials have seen significant progress during recent decades.The material properties are fully dependent on the compositions and structures of these compounds.As we known,III-V quaternary alloys are widely used to engineer the required combinations of specific bandgaps and band alignments to realize high-performance optoelectronic applications.However,as a critical challenge,immiscibility of quaternary alloy may make a degradation of the material's optical and electronic properties,which induce the major barriers in the realization of high performance optoelectronic devices.Therefore,it is important to develop a new strategy to solve immiscibility of quaternary alloy.We created a special In_xGa_1-xAs_ySb_1-y quaternary alloy.Through fractional monolayer alloy?FMA?epitaxy method on a vicinal surface,a vertical distribution of type-II In As/Ga Sb superlattices were introduced in quaternary alloy successfully.Then by manipulating superlattices' parameters,the components of alloys can be tuned,based on XRD and EDS results.Further,we used strain mapping results to prove the existence of vertical distribution of superlattices.More important,this type quaternary alloy has a mid-and long-infrared emission properties.As the most attractive material systems for high performance infrared range optoelectronic devices,III-V semiconductors superlattices have obtained a great attention in recent years.By now,superlattices based on In As/Ga Sb,In As/Ga?In?Sb and In As/Ga As Sb have been studied intensely to improve the performance of the IR range optoelectronic devices.However,it is generally believed that gallium?Ga?-related native defects in Ga Sb cause the minority carrier lifetime,which hinder device performance.To overcome this drawback,less Ga defects of superlattices are needed,such as In As/In As Sb.But,with characteristics of low absorption coefficient,quantum efficiency,and small overlap of electron and hole wavefunctions,T2 SLs based on In As/In Asy Sb1-y are still challenging.So in a word,the above superlattices,including In As/Ga Sb,In As/Ga?In?Sb,In As/Ga As Sb and In As/In As Sb are not satisfied for high performace IR range optoelectronic devices.Here,a novel In As?Sb?/ In_xGa_1-xAs_ySb_1-y type II superlattices are proposed and realized.In addition,a exclusive growth approach named fractional monolayer alloy?FMA?is developed to control components and tune superlattice structure.XRD measurements results indicate that the In As?Sb?/ In_xGa_1-xAs_ySb_1-y superlattices have excellent crystal quality.PL and k.p model calculation results indicated In As?Sb?/ In_xGa_1-xAs_ySb_1-y superlattices also exhibit superior optical properties benefit from high overlapping of wavefunctions of electron and hole induced by superlattices structure,which intensity is 7 times higher than In As/Ga Sb reference sample.Further,the growth of FMA prosess of In_xGa_1-xAs_ySb_1-y quarternary alloy enable flexibility of In As?Sb?/ In_xGa_1-xAs_ySb_1-y superlattices,which would be favorable for miniband engineering to cover mid-wavelength and long-wavelength infrared regions.