RII Track-4: Digital Alloy Contact Layers for Solar Cells

非技术描述提高太阳能系统的效率对于满足国家未来的能源需求至关重要。该项目旨在解决一个根本问题，即一种材料经常被要求在太阳能电池中执行多种功能，要求在极薄的薄膜中具有不同的性能。在这个项目中，PI和一名研究生将与国家可再生能源实验室(NREL)合作，研究特定薄膜的制备和表征及其在太阳能电池中的潜在应用。在以亚纳米分辨率制造这些薄膜的过程中，通过控制材料成分，将有可能最大限度地提高能量收集效率，并将几种太阳能电池技术中出现的损失降至最低，这是确保我们未来能源安全的关键一步。这项概念验证工作将为PI的总部机构(佛蒙特州大学)、佛蒙特州扩展的可再生能源研究社区和NRE之间未来的合作研究奠定坚实的基础。技术说明脉冲激光沉积(PLD)将被用于构建基于氧化锌的数字合金薄膜，使用掺杂(Ga)和等价取代基(MG)来调节薄膜中的载流子浓度和带隙。由于PLD生长的薄膜每单分子层需要多个激光脉冲，我们可以使用靶选择来控制Ga和Mg在数字合金薄膜生长方向上的位置。与NREL的合作将允许构建具有突变、周期性或梯度物理特性的薄膜。该项目将演示这种控制，并使用它来构建混合钙钛矿太阳能电池的选择性接触层，以最大限度地提高载流子收集并最大限度地减少氧化物界面的复合。预期的结果将是太阳能电池性能的明显改善。

Non-technical DescriptionIncreasing the efficiency of solar energy systems is critical to meeting the nation's future energy needs. This project seeks to address the fundamental problem that a single material is often called upon to perform multiple functions within a solar cell, demanding varying properties within extremely thin films. For this project, the PI and a graduate student will work with the National Renewable Energy Laboratory (NREL) to study the fabrication and characterization of specific thin films and their potential application in solar cells. By controlling the material composition during the fabrication of these films with sub-nanometer resolution, it will be possible to maximize the energy-harvesting efficiency and minimize losses that occur in several solar cell technologies, a critical step in securing our energy future. This proof-of-concept work will build a solid foundation for future collaborative research between the PI's home institution (University of Vermont), the extended renewable energy research community in Vermont, and NREL.Technical DescriptionPulsed laser deposition (PLD) will be used to construct digital alloy thin films based on ZnO, with dopants (Ga) and isovalent substituents (Mg) to adjust the carrier concentration and bandgap within the film. Because films grown by PLD require multiple laser pulses per monolayer of deposition, we can use target selection to obtain control of the position of the Ga and Mg in the direction of the digital alloy film growth. Collaboration with NREL will allow the construction of thin films that have abrupt, periodic, or gradient physical properties. The project will demonstrate this control and use it to construct selective contact layers for hybrid perovskite solar cells that maximize the carrier collection and minimize recombination at the oxide interface. The expected outcome will be a clear improvement in solar cell performance.