GaNP Based Coaxial Nanowires for Photovoltaic Applications

技术支持：本研究项目研究了稀氮化物GaNP核/壳纳米线的生长和特性，并研究了它们在高效太阳能电池应用中的潜力。稀氮化物GaNxP 1-x在常见的半导体中是独特的，因为它具有大的带隙弯曲，并且其带隙可以覆盖相对小浓度的氮的宽范围的太阳光谱。光子被吸收的核心和外壳的GaNxP 1-x/GaNyP 1-y核/壳纳米线，和光生电子和空穴被分离的II型交错带对齐的核心和外壳，放宽了在平面太阳能电池器件的长的少数载流子寿命的要求。基于氮化镓的同轴纳米线可能是一个可行的替代目前的三结技术，因为它对材料质量的要求不那么严格（由于自发的电子空穴分离），简单的加工（由于只有一个结），和较低的材料cost.Nontechnical：该项目解决了在材料科学的一个热门领域的基础研究问题，具有较高的技术相关性。这项研究如果成功，将对利用纳米科学和纳米技术开发太阳能电池产生重大影响。研究活动促进研究生和本科生在新型化合物半导体的生长和表征以及太阳能电池设计，制造和测试，以及书面和口头报告的跨学科培训。PI是加州州立数学与科学暑期学校（COSMOS）100多名高中生的暑期住宿计划的负责人。本研究结果可纳入课程，并透过COSMOS教师研究员计划推广至高中。

Technical: This research project investigates growth and properties of dilute nitride GaNP core/shell nanowires and studies their potential for efficient solar cell applications. The dilute nitride GaNxP1-x is unique among the common semiconductors in that it has a large bandgap bowing and its bandgap can cover a wide range of solar spectrum for relatively small concentrations of nitrogen. Photons are absorbed in both the core and the shell of the GaNxP1-x/GaNyP1-y core/shell nanowires, and photogenerated electrons and holes are separated by the type-II staggered band alignment of the core and the shell, relaxing the requirement of long minority carrier lifetime in a planar solar-cell device. The GaNP-based coaxial nanowires can potentially be a viable alternate to the current triple-junction technology because of its less stringent requirement on material quality (due to spontaneous electron hole separation), simpler processing (due to only one junction), and lower materials cost.Nontechnical: The project addresses basic research issues in a topical area of materials science with high technological relevance. The research, if successful, can have significant impacts on solar-cell development using nanoscience and nanotechnology. The research activities promote interdisciplinary training for graduate and undergraduate students in growth and characterization of novel compound semiconductors and in solar cell design, fabrication and testing, as well as written and oral presentations. The PI is the Director of the California State Summer School for Mathematics and Science (COSMOS) residential summer program for more than 100 high school students. The results of this research can be incorporated into the curriculum and extend to the high schools through the Teacher Fellow program of COSMOS.