Exploiting Luminescence Emissions of Solar Cells for Internet-of-Things Applications

在这个项目中，将开发一种利用光和太阳能电池进行无线通信的新型电子设备。关于太阳能电池的一个有趣的事实是，允许太阳能电池吸收光子的相同物理原理也允许它们在受到光或电的激励时发出光子。这种现象被称为发光。对于大多数太阳能电池来说，这种双向过程是不对称的。也就是说，光子吸收比光子发射更有效。这就是硅太阳能电池的情况。然而，还有其他材料，如砷化镓(GaAs)，在吸收和发射光子方面都是有效的。在这个项目中，由砷化镓太阳能电池发出的光将被调制以无线传输信息。使用这种方法的设备将能够使用他们的太阳能电池作为光学天线，通过光学方式发送和接收信息，同时从环境中捕获能量来为自己供电。这项拟议的技术将为连接到物联网(IoT)的设备提供一种新的通信手段。物联网以无缝的方式将互联网扩展到日常物品，目标是改善我们的生活。例如，建议的设备可以用于智能标签，以监控易腐烂商品在供应链中移动时的温度。它们还可以用于智能家居和智能工厂，将家用电器和工具连接到物联网。其他应用包括环境和农业监测。该项目将通过提供一类新的无线设备来推动电子和通信领域的发展。该项目还将加强对美国大学生和预科学生的教育，让他们参与研究活动，激发他们对科学、技术、工程和数学(STEM)的兴趣。该项目的目标是利用砷化镓太阳能电池的发光发射创造一种新型的光传输信息的无线设备。在此之前，太阳电池的缺陷和材料参数通常采用光致发光和电致发光来表征。在这里，通过调制发光发射的强度来将其用于无线通信。因此，该项目有可能开启光通信领域的一个新的研究领域，在该领域中，光被用来向无源设备传输能量和信息，以及从无源设备传输信息。鉴于这些设备将采用一种新的信息传输方法，该项目将解决几个基本问题和技术挑战，以使拟议的概念可行。特别是，本项目将解决下列问题：1)利用高效太阳能电池的调制发光发射，信息传输的速度有多快，距离有多远；2)发光调制的最佳方案是什么；3)什么电路架构和实现将产生最低的功耗；这些问题将通过以下研究任务来研究和回答：1)确定太阳能电池作为信息发送者和接收者的特征；2)选择合适的调制方案；3)开发可配置的硬件平台，以验证所选择的发光调制方案；4)开发低功耗平台，以演示拟议设备的自供电操作；5)测试硬件平台。这项拟议的研究将为物联网应用带来一种新的无线技术。与射频无线设备相比，这项技术的优势包括减少电磁干扰，避免大量使用和拥塞的射频频谱。其他优势包括使用基于相机的接收器进行精确发射器定位的能力，以及在水下工作的可能性。因此，拟议的技术具有创造新的商业应用和商业机会的潜力。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

In this project, a new type of electronic device that uses light and solar cells to communicate wirelessly will be developed. An interesting fact about solar cells is that the same physical principle that allows solar cells to absorb photons also allows them to emit photons when excited by light or electricity. This phenomenon is known as luminescence. For most solar cells, this bidirectional process is not symmetric. That is, photon absorption is more efficient than photon emission. This is the case for silicon solar cells. There are other materials, however, such as Gallium Arsenide (GaAs) that are efficient at both absorbing and emitting photons. In this project the light emitted by GaAs solar cells will be modulated to transmit information wirelessly. Devices that use this approach will be able to use their solar cells as optical antennas that transmit and receive information optically while capturing energy from their environment to power themselves. The proposed technology will provide a new means of communication for devices connected to the Internet-of-Things (IoT). The IoT extends the Internet to everyday objects in a seamless manner with the goal of enhancing our lives. For instance, the proposed devices can be used in smart labels to monitor the temperature of perishable goods as they move through the supply chain. They can also be used in smart homes and smart factories to connect appliances and tools to the IoT. Other applications include environmental and agricultural monitoring. This project will advance the field of electronics and communications by providing a new class of wireless devices. This project will also enhance the education of American college and pre-college students by involving them in research activities to stimulate their interests in Science, Technology, Engineering, and Mathematics (STEM).The objective of this project is to take advantage of the luminescence emissions of GaAs solar cells to create a new type of wireless device that transmits information optically. Previously, photo-luminescence and electro-luminescence emissions were employed to characterize defects and materials parameters of solar cells. Here, luminescence emissions are exploited for wireless communications by modulating their intensities. Hence, this project has the potential to start a new area of research in optical communications in which light is used to convey energy and information to and from passive devices. Given that these devices will employ a new approach to the transmission of information, the project will address several fundamental questions and technical challenges to make the proposed concept viable. In particular, this project will address the following questions: 1) how fast and how far can information be transmitted using modulated luminescence emissions from high-efficiency solar cells 2) what is the best scheme for luminescence modulation 3) what circuit architectures and implementations will yield the lowest power consumption These questions will be studied and answered through the following research tasks: 1) characterizing solar cells as transmitters and receivers of information; 2) selecting suitable modulation schemes; 3) developing configurable hardware platform to validate selected luminescence modulation schemes; 4) developing a low-power platform to demonstrate self-powered operation of the proposed devices; 5) testing the hardware platforms. The proposed research will result in a new wireless technology for IoT applications. Advantages of this technology over radio-frequency wireless devices include reduced electromagnetic interference and avoidance of heavily-used and congested radio frequency spectrum. Other advantages include the ability of precise transmitter localization using camera-based receivers and the possibility to work underwater. As such, the proposed technology has the potential for creating new commercial applications and business opportunities.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.