Metamorphic Antimonides for Infrared Photonics

摘要技术描述：本项目旨在发展外延生长变质锑基材料的技术，并研究其结构、光学和电学性质。这些半导体的基本吸收边可以在从近红外到远红外的宽光谱范围内变化。目前，由于外延层的直接生长受到二元衬底的限制，锑基半导体的全部技术潜力无法得到充分利用。外延层与衬底之间的大晶格失配导致晶体缺陷的高密度。基于对软锑化物材料中位错形成和位错运动的理解，组成梯度缓冲层的方法可以解决这一问题。关键因素是组成梯度缓冲层中的应变释放，限制了基底附近过渡区域的错配位错网络。晶格常数成为一个真正的设计参数，揭示了锑化物半导体提供的基本优势。窄带隙块体材料和在变质缓冲层上生长的异质结构的光学和电学性质的实验研究对于发展这类新型半导体性质的基础知识是必要的。非技术描述：锑基窄带隙半导体是发展高效光子和电子器件的重要材料，适用于各种工业和军事应用。将器件异质结构的晶格常数作为设计参数之一，可以充分发挥该类半导体的潜力。计划的研究直接关系到电子和光子器件的集成问题。外联活动扩大了研究的社会影响。从事各种光学传感器开发和实现的本科生和研究生将能够利用具有罕见光学和电学特性的新材料进行原始设计。

AbstractTechnical Description: The goal of this project is to develop the epitaxial technology to grow metamorphic antimonide-based materials and study their structural, optical and electrical properties. The fundamental absorption edge of these semiconductors can vary within a wide spectral range from near to far infrared. Currently the full technological potential of antimonide-based semiconductors cannot be utilized since the direct growth of epitaxial layers is limited by the availability of the binary substrates. The large lattice mismatch between the epitaxial layers and substrate leads to high densities of crystalline defects. The approach of compositionally graded buffer layers can address this issue based on understanding of the dislocation formation and dislocation motion in soft antimonide materials. The critical factor is strain relief in the compositionally graded buffer layer confining the network of misfit dislocations in the transitional region near the substrate. The lattice constant becomes truly a design parameter unveiling fundamental advantages offered by antimonide semiconductors. The experimental studies of the optical and electrical properties of narrow bandgap bulk materials and heterostructures grown on top of metamorphic buffers are necessary to develop the fundamental knowledge of the properties of this new class of semiconductors. Non-technical Description: Antimonide-based narrow bandgap semiconductors are important materials for development of the efficient photonic and electronic devices which are suitable for a variety of industrial and military applications. The potential of this class of semiconductors can be fully utilized when the lattice constant of the device heterostructure becomes one of the design parameters. The projected studies are directly related to the problem of integration of electronics and photonics devices. The societal impact of the research is amplified by outreach activities. Undergraduate and graduate students working on development and implementation of various optical sensors will be able to utilize novel materials with rare optical and electrical properties for their original designs.