SBIR Phase I: Advanced Nanomaterials Based on Quantum Dots with Built-in Charge for Sensing and Photovoltaics

这个小型企业创新研究第一阶段项目将专注于开发具有长光载流子寿命、低复合损耗和增强对红外(IR)辐射的耦合的新型光电纳米材料。实现这一点的创新是使用带有内置电荷的量子点(QD)来创建特定的三维势能分布，其中IR吸收区域(QD、QD行和QD团簇)通过势垒与导电通道分开。通过对点间距的选择性掺杂，实现了点的充电。由此产生的长光电子寿命将增加基于这一创新的传感器的光导增益和响应度。这种结构还将降低产生复合噪声，提高光电探测器的灵敏度。低复合损耗和增强对红外辐射的耦合将提高量子点太阳能电池的光伏效率。第一阶段的研究包括纳米级设计、生长和加工技术的开发，以及对测试结构和原型设备的综合分析。通过提供所需的基础和技术基础，该计划将开发具有多个光电子应用的先进纳米材料。该项目的更广泛的影响/商业潜力将是新型光电纳米材料的开发，这将导致红外传感和光伏领域的潜在突破。经过适当的修改，该技术几乎适用于任何方法制造的所有量子点材料和结构。光电纳米材料结合了对辐射的强耦合和长且可控的光载流子寿命，是发展下一代红外传感器的关键。在室温下工作的灵敏探测器将显著增加红外技术的商业市场，这些技术的应用包括工业和环境监测、化学传感、医疗诊断和爆炸物检测。这些结构的高可伸缩性为成像应用提供了广阔的机会。当集成到用于太阳能收集的In p-i-n结中时，这些结构将提供额外的~20%的转换效率提高(允许在没有聚光器的情况下总效率提高45%-50%)。在第一阶段项目中，我们将展示以这种方式收集和转换红外辐射至少使总转换效率增加7%。潜在的高效率和相对较低的成本(与高效的多结电池相比)使该技术在商业上适用于各种光伏应用。

This Small Business Innovation Research Phase I project will focus on development of novel optoelectronic nanomaterials with long photocarrier lifetimes, low recombination losses, and enhanced coupling to infrared (IR) radiation. The innovation which will enable this is the employment of quantum dots (QDs) with built-in charge to create specified three-dimensional potential profiles, where the areas of IR absorption (QDs, QD rows, and QD clusters) are separated from the conducting channels by potential barriers. The charging of dots is realized by selective doping of the interdot space. The resulting long photoelectron lifetime will increase the photoconductive gain and responsivity of sensors based on this innovation. This structure will also decrease the generation-recombination noise and improve the sensitivity of photodetectors. Low recombination losses and enhanced coupling to IR radiation will improve the photovoltaic efficiency of quantum dot solar cells. The Phase I research includes nanoscale design, development of growth and processing technologies, and comprehensive analyses of the test structures and prototype devices. By providing the needed fundamental and technological basis, this program will develop advanced nanomaterials with a number of optoelectronic applications.The broader impact/commercial potential of this project will be development of novel optoelectronic nanomaterials, which will lead to potential breakthroughs in IR sensing and photovoltaics. With appropriate modifications, the technology is applicable to practically all QD materials and structures fabricated by any method. Optoelectronic nanomaterials that combine strong coupling to radiation with long and manageable photocarrier lifetime are crucial for the development of next generation IR sensors. Sensitive detectors operating at room temperature will significantly increase the commercial market of IR technologies, which have applications including industrial and environmental monitoring, chemical sensing, medical diagnostics, and detection of explosives. The high scalability of these structures provides a wide opportunity for imaging applications. When integrated into in p-i-n junctions for solar energy harvesting, these structures will provide an additional ~20% improvement in the conversion efficiency (allowing 45-50% total efficiency without concentrators). In the Phase I project, we will demonstrate that harvesting and conversion of IR radiation in this way adds at least an additional 7% to the total conversion efficiency. The potential high efficiency and relatively low cost (as compared with efficient multi-junction cells) make this technology commercially viable for various photovoltaic applications.