Measuring Hole Transfer across the Single Nanowire/Liquid Interface

测量单纳米线/液体界面上的空穴传输

• 批准号: 1905312
• 负责人: Mario Alpuche Aviles
• 金额: $ 29万
• 依托单位: Board of Regents, NSHE, obo University of Nevada, Reno
• 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: 2019-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1905312&HistoricalAwards=false
• 关键词: Measuring; Hole; Transfer; across; Single

Semiconductor nanowires can be thousands of times thinner than a strand of hair. These extremely small sizes give rise to unique properties that can be harnessed for applications ranging from light emitting diodes to solar energy conversion devices. However, as the wire diameter gets smaller and smaller, defects at the nanowire surfaces, which trap charge and degrade device performance, play an ever-increasing role. With support from the Macromolecular, Supramolecular, and Nanochemistry program in the Division of Chemistry, Professor Mario Alpuche is studying the light-induced transfer of electrons between nanowires and molecules in solution. Working with his students, Professor Alpuche is using extremely small electrodes to detect the electrical current resulting from the absorption of light by a single nanowire. Their discoveries could have important implications for the use of nanomaterials in solar energy conversion applications. In addition, the project is broadening participation by recruiting students of Hispanic descent through engagement with educational programs throughout northern Nevada, and collaborations in the United States and abroad motivate students from underrepresented groups to pursue careers in chemistry.Professor Alpuche's research group is developing new methods to study charge transfer across the nanowire semiconductor surface. CdSe nanowires are attached to ultramicroelectrodes and excited with light, producing photogenerated electron-hole pairs. The hole in the valance band can be transferred from the nanowire to a molecule in solution, or trapped at surface defect sites, while the electron is transferred to the electrode and detected as a photoinduced current. The dependence of photocurrent on electrochemical potential and irradiation power enables a separation of the contribution of hole traps from that of charge transfer, and finite element simulations enable extraction of the rate constant for hole transfer out of the nanowire. The electrochemical instrumentation can detect photocurrent from individual nanowires, allowing the group to study the effects of nanowire heterogeneity across an ensemble of structures.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.

半导体纳米线可以比一根头发细几千倍。这些极小的尺寸产生了独特的性能，可以用于从发光二极管到太阳能转换设备的应用。然而，随着纳米线直径越来越小，纳米线表面缺陷的作用越来越大，这些缺陷会捕获电荷并降低器件的性能。在化学系大分子、超分子和纳米化学项目的支持下，Mario Alpuche教授正在研究溶液中纳米线和分子之间的光诱导电子转移。Alpuche教授和他的学生们一起使用极小的电极来检测由单根纳米线吸收光而产生的电流。他们的发现可能对纳米材料在太阳能转换应用中的应用具有重要意义。此外，该项目通过参与内华达州北部的教育项目招收西班牙裔学生，扩大了参与范围，并在美国和国外开展合作，鼓励来自代表性不足群体的学生从事化学事业。Alpuche教授的研究小组正在开发新的方法来研究纳米线半导体表面的电荷转移。CdSe纳米线附着在超微电极上，用光激发，产生光生成的电子-空穴对。价带中的空穴可以从纳米线转移到溶液中的分子中，或者被捕获在表面缺陷位置，而电子被转移到电极上并作为光感应电流被检测到。光电流对电化学电位和辐照功率的依赖使空穴阱的贡献与电荷转移的贡献分离开来，有限元模拟使空穴转移出纳米线的速率常数得以提取。电化学仪器可以检测来自单个纳米线的光电流，使研究小组能够研究纳米线非均质性对整体结构的影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Laser Induced Temperature Perturbation on Ultramicroelectrodes: Unsupported Solutions in Nonaqueous Methanol

超微电极上的激光诱导温度扰动：非水甲醇中的无支撑溶液

• DOI: 10.1149/1945-7111/ac49ca
• 发表时间: 2022
• 期刊: Journal of The Electrochemical Society
• 影响因子: 3.9
• 作者: Gutierrez-Portocarrero, Salvador;Subedi, Pradeep;Alpuche Aviles, Mario A.
• 通讯作者: Alpuche Aviles, Mario A.

Digital Processing for Single Nanoparticle Electrochemical Transient Measurements

单纳米颗粒电化学瞬态测量的数字处理

• DOI: 10.1021/acs.analchem.9b05238
• 发表时间: 2020
• 期刊: Analytical Chemistry
• 影响因子: 7.4
• 作者: Gutierrez-Portocarrero, Salvador;Sauer, Kiley;Karunathilake, Nelum;Subedi, Pradeep;Alpuche-Aviles, Mario A.
• 通讯作者: Alpuche-Aviles, Mario A.