More Like this

1. Solar harvesting through multiple semi-transparent cadmium telluride solar panels for collective energy generation

   https://doi.org/10.1016/j.solener.2023.112047  

   Katepalli, Anudeep; Wang, Yuxin; Shi, Donglu (November 2023, Solar Energy)

   Among major energy conversion methods, photovoltaic (PV) solar cells have been the most popular and widely employed for a variety of applications. Although a PV solar panel has been shown as one of the most efficient green energy sources, its 2D surface solar light harvesting has reached great limitations as it requires large surface areas. There is, therefore, an increasing need to seek solar harvest in a three-dimensional fashion for enhanced energy density. In addition to a conventional 2D solar panel in the x-y area, we extend another dimension of solar harvesting in the z-axis through multiple CdTe solar panels arranged in parallel. The high transparency allows sunlight to partially penetrate multiple solar panels, resulting in significantly increased solar harvesting surface area in a 3D fashion. The advantages of the 3D multi-panel solar harvesting system include: i) enlarged solar light collecting surface area, therefore increased energy density, ii) the total output power from multiple panels can exceed that of the single panel, and iii) significantly reduced surface area needed for densely populated cities. With five CdTe solar panels of different transparencies in parallel, the multilayer system can produce collective output power 233% higher than that of the single solar panel under the same surface area when arranged in descending (i.e., PV panel with the highest transparency on top and lowest at bottom). The PCE of the multi-panel system has also increased 233% in descending order indicating the viability of 3D solar harvesting. The multi-panel system will dimensionally transform solar harvesting from 2D to 3D for more efficient energy generation. 

   more » « less
2. Solar Harvesting through Multilayer Spectral Selective Iron Oxide and Porphyrin Transparent Thin Films for Photothermal Energy Generation

   https://doi.org/https://doi.org/10.1002/adsu.202100006  

   Lyu M., Lin J. (March 2021, Advanced sustainable systems)

   A fundamental challenge in energy sustainability is efficient utilization of solar energy towards energy-neutral systems. The current solar cell technologies have been most widely employed to achieve this goal, but are limited to a single-layer 2D surface. To harvest solar light more efficiently, a multilayer system capable of harvesting solar light in a cuboid through transparent photothermal thin films of iron oxide and a porphyrin compound is developed. Analogous to a multilayer capacitor, an array of transparent, spectral selective, photothermal thin films allows white light to penetrate them, not only collecting photon energy in a 3D space, but generating sufficient heat on each layer with significantly increased total surface area. In this fashion, thermal energy is generated via a multilayer photothermal system that functions as an efficient solar collector, energy converter and generator with high energy density. A solar-activated thermal energy generator that can produce heat without any power supply and reach a maximum temperature of 76.1 °C is constructed. With a constant incoming white light (0.4 W cm−2), the thermal energy generated can be amplified 12-fold via multilayers. The multilayer system extends another dimension in solar harvesting and paves a new path to energy generation for the energy-neutral system. 

   more » « less
3. Three-Dimensional Solar Harvesting with Transparent Spectral Selective Photovoltaics in Agrivoltaics

   https://doi.org/10.3390/en18071788  

   Shi, Donglu (April 2025, Energies)

   Although photovoltaic (PV) solar cells have been widely used for a variety of applications, several critical issues are yet to be addressed, including further enhanced power conversion efficiency (PCE) and their 2D solar harvesting with limited land availability. It has been reported that traditional PV installations require approximately 22,000 square miles to power the entire United States—posing a significant barrier, particularly in urban and agricultural settings. A unique dual modality of PV system has been proposed and implemented for both power generation and crop photosynthesis, namely, agrivoltaics. This system installs PV panels over the crops while harvesting solar for PV electricity generation and, at the same time, integrates with crop cultivation, which is a promising solution to optimize land utilization. However, for opaque PV panels, sunlight is often obstructed, potentially impacting plant growth and yield. To address this critical issue, a 3D solar harvesting concept has been proposed and experimentally investigated. By placing multiple layers of transparent PV panels parallel, sunlight can penetrate multiple layers and generate electricity on each PV, significantly enhancing the solar harvesting surface area. Most importantly, sunlight can also be collected by the crops underneath for effective photosynthesis. Among various PV materials, dye-sensitized solar cells (DSSCs) using porphyrin-based dyes have demonstrated potential for spectral modulation, optimizing both electricity generation and crop illumination. This review focuses on a novel approach to a 3D solar harvesting system via a multi-layered PV architecture for agrivoltaics. Also discussed are the current challenges in agrivoltaics, spectral selective mechanisms, and 3D solar harvesting architecture that show promise for sustainable energy production and land-efficient solar power deployment. 

   more » « less
4. Photothermal and photovoltaic properties of transparent thin films of porphyrin compounds for energy applications

   https://doi.org/https://doi.org/10.1063/5.0036961  

   Lin J., Shi D. (January 2021, Applied physics reviews)

   To address the critical issues in solar energy, the current research has focused on developing advanced solar harvesting materials that are low cost, lightweight, and environmentally friendly. Among many organic photovoltaics (PVs), the porphyrin compounds exhibit unique structural features that are responsible for strong ultraviolet (UV) and near infrared absorptions and high average visible transmittance, making them ideal candidates for solar-based energy applications. The porphyrin compounds have also been found to exhibit strong photothermal (PT) effects and recently applied for optical thermal insulation of building skins. These structural and optical properties of the porphyrin compounds enable them to function as a PT or a PV device upon sufficient solar harvesting. It is possible to develop a transparent porphyrin thin film with PT- and PV-dual-modality for converting sunlight to either electricity or thermal energy, which can be altered depending on energy consumption needs. A building skin can be engineered into an active device with the PT- and PV-dual modality for large-scale energy harvesting, saving, and generation. This review provides the current experimental results on the PT and PV properties of the porphyrin compounds such as chlorophyll and chlorophyllin. Their PT and PV mechanisms are discussed in correlations to their electronic structures. Also discussed are the synthesis routes, thin film deposition, and potential energy applications of the porphyrin compounds. 

   more » « less
5. Photothermal heating and solar harvesting through multiple transparent Fe3O4@Cu2-xS thin films with a solar dome

   https://doi.org/10.1016/j.enbuild.2026.117083  

   Gandharapu, Meher Saketh; Katepalli, Anudeep; Harfmann, Anton; Bonmarin, Mathias; Krupczak, John; Shi, Donglu (April 2026, Energy and Buildings)

   A novel building utility heating system is developed based on solar harvesting through multiple transparent photothermal (PT) panels arranged in a tunnel structure. Sunlight is collected by a rooftop solar dome and guided into a Photothermal Solar Tunnel (PTST), which achieves efficient conversion of solar radiation into thermal energy for passive heating. The PT panels are fabricated from thin films of Fe₃O₄@Cu₂₋ₓS plasmonic nanoparticles, which, due to localized surface plasmon resonance (LSPR), exhibit strong absorption in the UV and IR regions while maintaining minimal absorption in the visible band. This unique optical property enables high average visible transmittance (AVT), allowing sunlight to penetrate sequential panels within the PTST while the system functions as a transparent heat radiator. Controlled experiments under diverse environmental conditions, including extreme subzero temperatures, demonstrate the PTST’s strong heating capability: interior tunnel surfaces reached above 30.9 °C from ambient temperatures of −7 °C with only minimal insulation. These results establish PTST as a scalable, cost-effective, and off-grid technology for sustainable building heating. By eliminating the need for complex solar system integration or bulky components, this approach opens a new pathway for passive solar energy utilization, advancing energy-neutral and environmentally resilient solutions for next-generation buildings. 

   more » « less