Triple Halide Ultrawide Bandgap Metal Halide Perovskites

三卤化物超宽禁带金属卤化物钙钛矿

• 批准号: 2245435
• 负责人: Michael McGehee
• 金额: $ 65万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2245435&HistoricalAwards=false
• 关键词: Triple; Halide; Ultrawide; Bandgap; Metal

Non-technical DescriptionMetal halide perovskites are solution-processed semiconductors with attractive optical and electronic properties, which have enabled the fabrication of efficient and low-cost devices such as solar cells and light-emitting diodes (LEDs). Perovskites used in the most efficient devices to date absorb light in the red and near-infrared. This corresponds to a band gap of 1.2 to 1.8 electron volts (eV), with an eV being the amount of energy needed to move an electron across an electric potential of one volt. It is desirable to develop high quality materials with higher band gaps to capture more of the sun’s energy in a solar cell or emit green or blue light from an LED. The team hypothesizes that perovskites with three different halide atoms could realize these high-quality materials with increased band gaps. The team will fabricate triple-halide perovskites and thoroughly characterize their structure, composition and properties. In doing so the team will expand the range of viable perovskites for device applications. This work will be done collaboratively between the University of Colorado Boulder and Wellesley College. Wellesley College is a diverse women’s undergraduate college, where a majority of the incoming class identifies as people of color. Wellesley College undergraduates work closely with researchers at major academic institutions and national laboratories. This greatly increases their research opportunities and provides students with exposure to graduate programs. This project will serve to support that population and expand STEM opportunities.Technical DescriptionThe goal of this project is to synthesize high performance all-inorganic perovskite semiconductors with bandgaps between 1.9 and 2.1 eV. The performance of current wide bandgap perovskites is limited by non-radiative recombination and environmental instability. Triple halide perovskites are hypothesized to have desirable properties because there will be no opportunity for demixing to occur at the A-site, chlorine will passivate defects, the small lattice parameter will result in strong bonds and there will be no organic cation that could decompose. The team will investigate a range of promising triple halide perovskites, leveraging its expertise to characterize and understand the miscible composition space; map and understand the instabilities in these materials; and ultimately quantify and optimize the optoelectronic properties of select triple halide perovskites. The team will determine how solution chemistry impacts perovskite nucleation, film growth and performance and resultant optoelectronic properties and stability. The team will document improvements using cyclic voltammetry, in situ photoluminescence and absorption spectroscopy, and X-ray diffraction to map defect densities and barriers to degradation. This project is working towards (1) optimized synthesis of novel triple halide perovskites; (2) quantification of the stability of wide bandgap perovskites and optoelectronic performance; and (3) improved interfacial layers for surface passivation and carrier selection in wide bandgap perovskites.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.

非技术性描述金属卤化物钙钛矿是经过溶液处理的半导体，具有有吸引力的光学和电子特性，可用于制造高效且低成本的器件，例如用于最高效器件的太阳能电池和发光二极管 (LED)。迄今为止，它吸收红光和近红外光，这对应于 1.2 至 1.8 电子伏特 (eV) 的带隙，其中 eV 是能量的大小。需要开发具有更高带隙的高质量材料，以在太阳能电池中捕获更多的太阳能或从 LED 发出绿光或蓝光。具有三种不同卤化物原子的钙钛矿可以实现这些具有更大带隙的高质量材料，该团队将制造三卤化物钙钛矿，并彻底表征其结构、成分和性能，从而扩大用于器件的可行钙钛矿的范围。这项工作将由科罗拉多大学博尔德分校和韦尔斯利学院合作完成，韦尔斯利学院是一所多元化的女子本科学院，其中大多数新生都是有色人种，与主要学术领域的研究人员密切合作。这大大增加了他们的研究机会，并为学生提供了接触研究生课程的机会。该项目将有助于支持该人群并扩大 STEM 机会。技术描述该项目的目标是合成高性能全无机材料。带隙在 1.9 至 2.1 eV 之间的钙钛矿半导体当前宽带隙钙钛矿的性能受到非辐射复合和环境不稳定性的限制，因为在 A 处不会发生分层，因此三卤化物钙钛矿具有理想的性能。 -位点，氯会钝化缺陷，小的晶格参数将导致牢固的键合，并且不会有可能分解的有机阳离子。将研究一系列有前景的三卤化物钙钛矿，利用其专业知识来表征和了解可混溶的成分空间；绘制并了解这些材料的不稳定性；并最终量化和优化选定的三卤化物钙钛矿的光电特性。溶液化学影响钙钛矿成核、薄膜生长和性能以及由此产生的光电性能和稳定性，该团队将记录使用循环伏安法、原位光致发光和吸收的改进。该项目致力于 (1) 新型三卤化物钙钛矿的优化合成；(2) 宽带隙钙钛矿的稳定性和光电性能的量化； ）改进了宽带隙钙钛矿表面钝化和载流子选择的界面层。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准。