Collaborative Research: Predictive theory, synthesis and characterization of a new type of transparent conductor without doping

合作研究：新型无掺杂透明导体的预测理论、合成和表征

基本信息

批准号：
1806912
负责人：
Kenneth Poeppelmeier
金额：
$ 27万
依托单位：
Northwestern University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-07-01 至 2022-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1806912&HistoricalAwards=false
关键词：
Collaborative Research Predictive theory synthesis

项目摘要

Non-technical description: Technologies such as photovoltaic solar cells, smart windows, light emitting diodes, touch-screen sensors, electronic papers, and flat panel displays require for their operation a critical component that is both an electrical conductor and optically transparent, the so-called transparent conductors. These compounds are unique, as transparency and conductivity are generally mutually exclusive properties of compounds. Indeed, optical transparency (as in window glass) is generally associated with electrical insulation, whereas electrical conductivity (such as in copper or gold) is generally associated with optically opaque metals. Known transparent conductors such as indium oxide doped with Sn are made by instilling conductivity in transparent insulators. The research team aims to develop a novel family of transparent conductors - metallic ceramics - by designing transparency in metals. This presents a new method to design optical properties as distinct from electronic properties. The approach has an exciting intellectual impact as it suggests a general approach for inverse design - starting from science-based design principles used as 'filters' for computational material selection, followed by identification of representative examples and then laboratory validation. The graduate students and postdocs of CU Boulder and Northwestern Universities are given exciting opportunities to participate in this cutting edge research effort.Technical description: Transparent conducting oxides are paradoxical materials that form the basis of modern day technologies, such as touch screens, flat panel displays, solar panels, etc. The current method of choice for discovering new transparent conductors have relied on heavily doping transparent insulators until they become conducting. Unfortunately, wide band gap materials are intrinsically resistant to doping of charges because of the existence of so-called 'doping bottlenecks'. Namely, the introduction of a high concentration of free carriers into insulators generally leads to the spontaneous formation of structural defects with polarity that compensate that of the intentional doping. Consequently, the progress in finding and optimizing such technologically critical transparent conducting oxide materials has been frustratingly slow. The research team proposes an opposite, and likely more fruitful alternative of designing transparency in metals by looking for compounds that obey a set of 'design principles' with specific band structures. The design rules for such intrinsic transparent conductors are: (i) identify a compound with metallic band structure; such that (ii) it has low plasma frequency and (iii) low inter-band optical absorption across the Fermi level, and (iv) apply synthesis and characterization to the 'best of class' compounds, here Ba-Nb-O. The most visible advantage of metallic transparent conductors is that their conductivity comes from their high, indigenous carrier concentration. The complex theory-experimental approach in the proposal enables more efficient progress as alternative to the previously used trial-and-error method.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术描述：诸如光伏太阳能电池，智能窗户，发光二极管，触摸屏传感器，电子纸和平面面板显示器需要其操作，这既是电气导体，又是光学透明的，SO都需要其操作 - 称为透明导体。这些化合物是独一无二的，因为透明度和电导率通常是化合物的相互排斥特性。实际上，光学透明度（如在窗玻璃中）通常与电绝缘有关，而电导率（例如铜或金中）通常与光学上不透明的金属有关。已知的透明导体，例如用SN掺杂的氧化二氧化物，是通过在透明绝缘体中灌输电导率的。研究小组旨在通过设计金属的透明度来开发一个新型的透明导体家族 - 金属陶瓷。这提出了一种设计与电子特性不同的设计光学特性的新方法。该方法具有令人兴奋的智力影响，因为它提出了一种逆设计的一般方法 - 从基于科学的设计原理作为计算材料选择的“过滤器”，然后确定代表性示例，然后再确定实验室验证。 Cu Boulder和Northwestern大学的研究生和博士学位都有令人兴奋的机会参加这项尖端研究工作。技术描述：透明的导电氧化物是矛盾的材料，构成了现代技术的基础，例如触摸屏，平面面板显示器，平面面板显示器，太阳能电池板等。发现新的透明导体的当前首选方法依赖于泛滥的透明绝缘体，直到它们进行操作为止。不幸的是，由于存在所谓的“掺杂瓶颈”，因此宽带间隙材料本质上具有对电荷掺杂的抗掺杂。也就是说，将高浓度的自由载体引入绝缘子通常会导致具有极性的结构缺陷的自发形成，从而补偿了故意掺杂的掺杂。因此，查找和优化这种技术关键的透明导电氧化物材料的进展非常缓慢。研究团队提出了一种相反的选择，即通过寻找遵守特定带结构的一组“设计原理”的化合物来设计金属中的透明度。这种内在透明导体的设计规则是：（i）确定具有金属带结构的化合物；这样的（ii）它具有低血浆频率和（iii）在费米水平上的波带间光吸收低，并且（iv）将合成和表征应用于“最佳类”化合物，此处是BA-NB-O。金属透明导体最明显的优势是它们的电导率来自其高，土著载体浓度。该提案中复杂的理论实验方法可以使更有效的进步作为先前使用的试验方法的替代方案。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和更广泛影响评论来评估值得支持的。标准。