NSF-BSF: High-mobility amorphous-iodide-based channel materials for p-type thin-film transistors and complementary TFT circuitry

NSF-BSF：用于 p 型薄膜晶体管和互补 TFT 电路的高迁移率非晶碘化物沟道材料

• 批准号: 1904633
• 负责人: David Paine
• 金额: $ 47万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1904633&HistoricalAwards=false
• 关键词: NSF; BSF; mobility; amorphous; iodide

Nontechnical description: Over the past decade, displays in electronic devices like laptops have been revolutionized in part by using transparent conducting amorphous oxides due to their processing versatility and higher carrier mobility combined with low-temperature, large-area deposition conditions. A team of investigators from Brown University and Technion (Israel) is investigating a new class of materials, amorphous metal iodides like CuSnI and CuPbI, that would add to the arsenal of transparent conducting materials for use in displays and other transparent circuit technologies. Compared to other amorphous materials, the amorphous metal iodides feature a different physical mechanism: under an applied voltage, the currents are carried by positively charged holes. This offers new low-power dissipation circuit possibilities, as long as the materials properties of these metal iodides, including impurity content, phase, and temperature behavior can be tuned using composition and processing parameters. The research program covers a number of topics, ranging from fundamental experimental materials science of material deposition and characterization to theoretical modeling of phase transformation and impurity incorporation to prototype transistor device fabrication, brings together transparent electronic material and device expertise at Brown University with cutting-edge materials characterization and modeling at the Technion. The research project has an educational impact in and out of the classroom, including graduate student support, Brown-Technion graduate student interaction and exchange visits, as well as outreach to underprivileged middle-school students in the Providence area.Technical description: Two Brown experimentalists with complementary expertise in amorphous electronic materials and device physics, in collaboration with a Technion team experienced in atomic/nano/micro characterization and physical modeling, are focusing on the need for a high-mobility wide-bandgap low-temperature p-type material for thin film transistors (TFTs). The PIs have identified amorphous iodide-based materials as the most promising: they have a wide bandgap (3 eV), high hole mobility (up to 40 cm2/V.s), native vacancy doping, and are compatible with arbitrary substrates. They are also compatible with low-temperature-deposited amorphous n-type zinc oxide-based materials, opening the way for complementary TFT circuitry. The Brown PIs are leveraging their recent demonstration of high-performance indium-zinc-oxide materials by reconfiguring an oxide sputtering tool for in-situ iodide deposition. The Brown team is developing and optimizing the synthesis of a-Cu1-xMxI thin films (M = Sn, Pb, In, and others), studying the doping mechanism via Brouwer analysis, investigating phase stability, and fabricating prototype TFT demonstrator circuits. The experimental work is complemented by the detailed materials characterization and physical modeling performed by the Technion team, that has extensive experience in nanoscale amorphous and crystalline films. The final experimental goal is to develop the deposition of both n- and p-type transparent conducting materials in the same sputter-deposition process at low temperature on arbitrary substrates. The project provides training opportunities to the participating graduate and undergraduate students in cross-cutting electronic materials and devices fields, to the Brown-Technion visitor and student exchanges, as well as to the local underprivileged middle-school students.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：在过去的十年中，由于透明导电非晶氧化物的加工多功能性和更高的载流子迁移率与低温、大面积沉积条件相结合，笔记本电脑等电子设备中的显示器已经发生了部分革命。来自布朗大学和以色列理工学院的一个研究小组正在研究一种新型材料，即 CuSnI 和 CuPbI 等非晶态金属碘化物，这将丰富用于显示器和其他透明电路技术的透明导电材料。与其他非晶材料相比，非晶金属碘化物具有不同的物理机制：在施加电压下，电流由带正电的空穴承载。只要这些金属碘化物的材料特性（包括杂质含量、相和温度行为）可以使用成分和工艺参数进行调整，这就提供了新的低功耗电路的可能性。该研究项目涵盖了许多主题，从材料沉积和表征的基础实验材料科学到相变和杂质掺入的理论建模，再到原型晶体管器件制造，汇集了布朗大学的透明电子材料和器件专业知识与尖端技术以色列理工学院的材料表征和建模。该研究项目对课堂内外都有教育影响，包括研究生支持、布朗-以色列理工学院研究生互动和互访，以及对普罗维登斯地区贫困中学生的外展。技术描述：两名布朗实验员凭借在非晶电子材料和器件物理方面的互补专业知识，与在原子/纳米/微米表征和物理建模方面经验丰富的以色列理工学院团队合作，重点关注高迁移率宽带隙低温 p 型材料的需求薄膜晶体管 (TFT)。 PI 认为非晶碘化物基材料是最有前途的：它们具有宽带隙 (3 eV)、高空穴迁移率（高达 40 cm2/V.s）、原生空位掺杂，并且与任意基材兼容。它们还与低温沉积的非晶 n 型氧化锌基材料兼容，为互补 TFT 电路开辟了道路。 Brown PI 正在利用他们最近展示的高性能氧化铟锌材料，重新配置用于原位碘化物沉积的氧化物溅射工具。 Brown 团队正在开发和优化 a-Cu1-xMxI 薄膜（M = Sn、Pb、In 等）的合成，通过 Brouwer 分析研究掺杂机制，研究相位稳定性，并制造原型 TFT 演示电路。以色列理工学院团队在纳米级非晶态和晶体薄膜方面拥有丰富的经验，他们进行的详细材料表征和物理建模对实验工作进行了补充。最终的实验目标是开发在相同的低温溅射沉积工艺中在任意基材上沉积 n 型和 p 型透明导电材料的方法。该项目为参与的研究生和本科生提供交叉电子材料和器件领域的培训机会，为布朗以色列理工学院的访问者和学生交流项目，以及当地贫困中学生提供培训机会。该奖项体现了 NSF 的法定使命通过使用基金会的智力优点和更广泛的影响审查标准进行评估，并被认为值得支持。