Development of Quaternary Diamond-like Semiconductors for Infrared Nonlinear Optical Applications

用于红外非线性光学应用的四元类金刚石半导体的开发

• 批准号: 1611198
• 负责人: Jennifer Aitken
• 金额: $ 44.5万
• 依托单位: Duquesne University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1611198&HistoricalAwards=false
• 关键词: Development; Quaternary; Diamond; like; Semiconductors

Non-Technical AbstractNonlinear optical (NLO) crystals are used to shift the coherent, monochromatic light of lasers to other desirable wavelengths. Infrared nonlinear optical applications include, stand-off detection of drugs and explosives, non-invasive medical diagnosis and monitoring by breath analysis using molecular spectroscopy and infrared counter-measure systems used to defend military aircraft, just to name a few. However, the current commercially available crystals for use in infrared nonlinear optical devices suffer from drawbacks and are lacking in critical areas that limit their practical applications. The discovery of new infrared nonlinear optical materials enables the realization of new applications impacting medical, industrial and military sectors. Furthermore, the synthesis of improved infrared nonlinear optical materials allows for more reliable, longer-lasting devices having greater impact in areas where these materials have already found utility. Better understanding the relationship between the structure of the crystal and its resulting properties allows for faster progress in this field. Through this project, structure-property correlations are evolving from systematic studies of quaternary diamond-like semiconductors that combine strategic experimentation with theory, in which the ability to reliably predict properties is fostered by experimental results. These structure-property relationships are being revealed by the research efforts of postdoctoral fellows, graduate students, undergraduate researchers, high school science teachers and high school students on the research team. X-ray powder diffraction workshops organized through this project are training the next-generation workforce to solve complex scientific problems with the use of advanced research tools. Outreach activities geared toward women, minorities and economically disadvantaged students are taking place through the research group's participation in the ACS Project SEED program and interactions with local undergraduate women in STEM fields.Technical AbstractCurrent commercially available infrared nonlinear optical crystals have shortcomings, such as a lack of power-handling ability and multiphoton absorption effects that preclude usage with high-powered lasers and operation at certain wavelengths, respectively. This project, supported by the Solid State and Materials Chemistry program, focuses on the synthesis and characterization of quaternary diamond-like semiconductors and the assessment of their potential as new infrared nonlinear optical materials. Nonlinear optical (NLO) properties on powdered diamond-like semiconductor samples and additional properties of centimeter-sized single crystals are being assessed. The powdered/microcrystalline compound samples are prepared by high-temperature solid-state or lithium polysulfide flux synthesis. Second-order nonlinear optical susceptibility, laser damage threshold and the onset wavelength for phase matchability, as well as transparency range and bandgap are being measured. The preparation of centimeter-scale single crystals of selected compounds identified as promising candidates is being carried out via the vertical Bridgman method and iodine-vapor transport reactions. Certain properties of technological importance, including thermal conductivity and extreme optical transparency measured by laser calorimetry, are being assessed using these sizeable single crystals. Relationships between the composition, crystal structure and electronic structure of the materials, especially bandgap, and the observed physical properties are being considered to build crystal-chemical concepts that allow for knowledge-based optimization of materials' NLO properties.

非技术摘要非线性光学 (NLO) 晶体用于将激光的相干单色光转移到其他所需的波长。红外非线性光学应用包括药物和爆炸物的远距离检测、非侵入性医疗诊断以及使用分子光谱进行呼吸分析的监测以及用于保卫军用飞机的红外对抗系统等等。然而，目前市售的用于红外非线性光学器件的晶体存在缺陷并且缺乏限制其实际应用的关键领域。新型红外非线性光学材料的发现使得影响医疗、工业和军事领域的新应用得以实现。此外，改进的红外非线性光学材料的合成可以实现更可靠、更持久的设备，在这些材料已经得到应用的领域产生更大的影响。更好地了解晶体结构及其产生的特性之间的关系可以使该领域取得更快的进展。通过该项目，结构-性能相关性从四元类金刚石半导体的系统研究中演变而来，该研究将战略实验与理论相结合，其中实验结果培养了可靠预测性能的能力。研究团队中的博士后、研究生、本科生研究人员、高中科学教师和高中生的研究工作正在揭示这些结构与性质的关系。通过该项目组织的 X 射线粉末衍射研讨会正在培训下一代劳动力，以利用先进的研究工具解决复杂的科学问题。通过研究小组参与 ACS 项目 SEED 计划以及与 STEM 领域的当地女本科生的互动，针对女性、少数族裔和经济困难学生开展了外展活动。 技术摘要 目前市售的红外非线性光学晶体存在一些缺点，例如缺乏功率处理能力和多光子吸收效应分别阻碍了高功率激光器的使用和在某些波长下的操作。该项目由固态和材料化学项目支持，重点关注四元类金刚石半导体的合成和表征以及评估其作为新型红外非线性光学材料的潜力。粉末状类金刚石半导体样品的非线性光学（NLO）特性以及厘米级单晶的其他特性正在评估中。粉末/微晶化合物样品是通过高温固态或多硫化锂熔剂合成制备的。正在测量二阶非线性光学磁化率、激光损伤阈值和相位匹配性的起始波长，以及透明度范围和带隙。被确定为有希望的候选化合物的厘米级单晶的制备正在通过垂直布里奇曼法和碘蒸气传输反应进行。某些具有技术重要性的特性，包括热导率和通过激光量热法测量的极端光学透明度，正在使用这些相当大的单晶进行评估。人们正在考虑材料的成分、晶体结构和电子结构（尤其是带隙）与观察到的物理性质之间的关系，以建立晶体化学概念，从而可以基于知识优化材料的非线性光学性质。