UNS: Performance Optimized Intermediate Band Photovoltaic Devices based on Type-II Quantum Dots

UNS：基于II型量子点的性能优化中波段光伏器件

• 批准号: 1512017
• 负责人: Igor Kuskovsky
• 金额: $ 30万
• 依托单位: CUNY Queens College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-15 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1512017&HistoricalAwards=false
• 关键词: UNS; Performance; Optimized; Intermediate; Band

PI: Igor L KuskovskyProposal Number: 1512017The sun represents the most abundant potential source of sustainable energy on earth. Solar cells made from thin films of nanometer-sized crystals called quantum dots are potentially less expensive and more efficient than crystalline silicon solar cells currently in commercial use. The goal of this project is to engineer the composition and size of the quantum dots to enhance the collection of solar energy in the ultraviolet and infrared wavelengths of the solar spectrum, resulting in potentially high solar energy conversion efficiency and power output. The quantum dots will be made from mixtures of the elements zinc, selenium, cadmium, and tellurium as model compounds for scientific study. The composition of these mixtures will be guided by computer simulations. The proposed research may lead to the discovery of new quantum mechanical processes for solar energy conversion. As part of the educational activities associated with the project, the principal investigator will mentor high school students through Queens College Summer Science Program on nanotechnology related projects for science fair competitions in the state of New York. The overall goal of the proposed research is to develop Type-II quantum-dot photovoltaic (PV) semiconductor materials that enable the absorption of light below the band gap of the host material, leading to higher solar energy conversion efficiency. Toward this end, Type-II quantum dots will be imbedded into a wide band-gap semiconductor host to make an intermediate band gap material with photon absorption characteristics mapped to the solar spectrum in the ultraviolet to infrared range, using material systems and synthesis approaches that lead to increase of photocurrent without loss of open circuit voltage. Toward this end, the research plan will integrate material synthesis, band gap calculations, and PV device simulation to identify ideal intermediate band gap PV materials. The candidate material systems consist of a p-ZnSeTe/Zn(Cd)Te-ZnCdSe/n-ZnCdSe structure with embedded Zn(Cd)Te-ZnCdSe type-II quantum dots. The barriers, latticed matched to the InP substrate, have the bandgaps of about 2.1 eV, while the quantum dots have a valence band offset of 0.8-1.0 eV. These parameters will be achieved by controlling quantum dot size and chemical composition. To accomplish effective partial filling of the intermediate band, a structure with alternatively doped quantum dot layers will be engineered. Film growth will be designed to avoid formation of a wetting layer that can lower the open circuit voltage of the final material. This process will also allow for the deposition of several hundred defect-free quantum dot layers for improved light absorption. Device-level simulation will characterize the interplay between device configuration and recombination processes associated with these intermediate band gap materials. Based on the research, instructional material will be developed on the topic of fabrication of Type-II quantum dots for solar cell applications, and will be used in courses for a professional Master's degree program in Photonics at Queens College, The City College of New York.

PI：Igor L Kuskovsky建议编号：1512017太阳代表着地球上最丰富的可持续能源的潜在来源。太阳能电池由纳米尺寸的晶体薄膜制成，称为量子点，可能比目前商业使用的晶体硅太阳能电池更便宜，更有效。 该项目的目标是设计量子点的组成和大小，以增强太阳光谱中紫外和红外波长的太阳能收集，从而获得潜在的高太阳能转换效率和功率输出。 量子点将由锌、硒、镉和碲元素的混合物制成，作为科学研究的模型化合物。 这些混合物的组成将由计算机模拟指导。 这项研究可能会发现太阳能转换的新量子力学过程。 作为与该项目相关的教育活动的一部分，首席研究员将通过皇后学院暑期科学计划指导高中学生参加纽约州科学博览会竞赛的纳米技术相关项目。拟议研究的总体目标是开发II型量子点光伏（PV）半导体材料，使光吸收低于主体材料的带隙，从而提高太阳能转换效率。 为此，II型量子点将嵌入宽带隙半导体主体中，以制造具有光子吸收特性的中间带隙材料，该光子吸收特性映射到紫外到红外范围内的太阳光谱，使用材料系统和合成方法，导致光电流增加而不损失开路电压。为此，研究计划将整合材料合成，带隙计算和PV器件模拟，以确定理想的中间带隙PV材料。候选材料系统由嵌入Zn（Cd）Te-ZnCdSe II型量子点的p-ZnSeTe/Zn（Cd）Te-ZnCdSe/n-ZnCdSe结构组成。与InP衬底晶格匹配的势垒具有约2.1eV的带隙，而量子点具有0.8- 1.0eV的价带偏移。这些参数将通过控制量子点尺寸和化学成分来实现。为了实现中间带的有效部分填充，将设计具有交替掺杂的量子点层的结构。 膜生长将被设计成避免形成可降低最终材料的开路电压的润湿层。该过程还将允许沉积数百个无缺陷的量子点层以改善光吸收。 器件级模拟将表征与这些中间带隙材料相关的器件配置和复合过程之间的相互作用。 根据这项研究，将开发关于太阳能电池应用的II型量子点制造主题的教学材料，并将用于纽约城市学院皇后学院光子学专业硕士学位课程的课程。