CAREER: Band Engineering in Amorphous Semiconductors

非技术描述：今天的核心？S电子都是半导体材料。半导体强烈吸收光的光能称为它的带隙。通过混合两种不同的材料来形成半导体合金，它的带隙可以被调节。该项目的第一个目标是研究由非晶态或无序氧化物半导体制成的合金的基本材料性质和带隙调节。这些宽带隙材料较少被开发，但在可再生能源和医疗保健设备等具有很强社会意义的应用中非常有希望。该项目的第二个目标是通过让整个研究团队参与公众，包括学龄儿童的外联活动，将研究和教育结合在一起。此外，首席调查员通过研究活动和职业联系为研究生和本科生提供指导。技术描述：该项目通过四元和五元合金化探索非晶氧化物半导体薄膜的能带工程。这些材料具有很宽的禁带，类似于氮化镓。多组分相图被用来将氧化物合金成分与热力学稳定性和材料性能联系起来。该项目的具体目标是：(1)研究亚稳定带工程非晶合金薄膜的合金成分范围和热力学途径；(2)利用电学和光电子技术表征作为合金成分函数的电荷输运和亚带隙密度；(3)建立模型并实验验证非晶氧化物合金中异质结构界面的形成。通过这些研究，本项目大大扩展了目前对无序半导体的科学认识和应用范围。利用这些带状非晶氧化物合金制作的异质结可用于未来的高功率电子学或深紫外光电子器件。

Non-Technical Description: At the core of today?s electronics are semiconductor materials. The optical energy at which a semiconductor strongly absorbs light is known as its bandgap. By mixing two different materials to form a semiconductor alloy, its bandgap can be tuned. The first goal of this project is to study the fundamental materials properties and bandgap tuning in alloys made of amorphous, or disordered, oxide semiconductors. These wide bandgap materials are less explored but very promising for applications of strong societal importance such as devices for renewable energy and health care. The second goal of this project is to bring together research and education by engaging the entire research team in outreach activities with the public, including school-age learners. In addition, the principal investigator provides mentoring to graduate and undergraduate students through research activities and ?Career Connections? events featuring discussions with practicing scientists and engineers.Technical Description: This project explores band engineering of amorphous oxide semiconductor thin films via quaternary and quinary alloying. These materials have a wide bandgap, similar to that of gallium nitride. Multi-component phase diagrams are used to relate oxide alloy composition to thermodynamic stability and materials properties. The specific objectives of this project are: (i) to investigate the alloy composition ranges and thermodynamic pathways available for meta-stable band-engineered amorphous alloy films; (ii) to characterize charge transport and sub-bandgap density of states as a function of alloy composition, using electrical and opto-electronic techniques; (iii) to develop models and experimentally validate hetero-structure interface formation in amorphous oxide alloys. Through these studies, this project significantly expands the present scientific understanding and application scope of disordered semiconductors. Heterostructures made using these band-engineered amorphous oxide alloys can be used in future high-power electronics or deep ultraviolet optoelectronics devices.