Combining Photosynthesis and Photovoltaics: A Hybrid Energy-Harvesting System Using Optical Antennas

Abstract

A hybrid energy-harvesting system is proposed that combines photosynthesis and photovoltaics. First, the light passes through a spectrally selective solar cell, which absorbs almost all green light but absorbs almost no blue and red light. The blue and red light are absorbed by a photosynthesis executing plant. The solar cell is tailored in such a way that the photosynthetic process is almost unaffected by the generation of electrical energy. The spectrally selective solar cell consists of an array of inorganic optical antennas. By combining a spectrally selective solar cell and a photosynthetic executing plant, a hybrid energy system is formed, which absorbs almost 100% of the visible light, while the energy conversion efficiency of the solar cell reaches up to 50% of their nonspectrally selective counterparts. Guidelines are provided on how to realize both the highly efficient spectrally selective solar cells and hybrid energy-harvesting systems. The proposed solution allows for the realization of new greenhouses or gardens covered with spectrally selective transparent solar cells that produce chemical energy in the form of fruits and vegetables and electrical energy.

Band-Gap-Engineered Transparent Perovskite Solar Modules to Combine Photovoltaics with Photosynthesis

“…Recently, a third approach has been proposed in the literature by two authors of this study, a solar cell using optical antennas built from inorganic materials. 13 It is the first time that such a solar cell is proposed using inorganic materials. However, the realization of the solar cells requires the fabrication of periodic nanowire arrays with diameters down to less than 100 nm on large areas.…”

“…Recently, two authors of this study have proposed a solution using optical antennas integrated in solar cells. 13 The optical antennas consist of nanowires or pillars made of inorganic semiconducting materials like silicon. The devices allow for the selective absorption of green light, while red light is not absorbed and blue light is only partially absorbed.…”

“…The devices allow for the selective absorption of green light, while red light is not absorbed and blue light is only partially absorbed. 13 However, the diameter of the nanowires is significantly smaller than the incident light wavelength. Hence, the device fabrication is challenging because nanostructures must be manufactured on large areas with high precision.…”

Resonant tunneling in natural photosynthetic systems

“…In particular, the internal quantum efficiency or photon-energy-charge conversion efficiency of photosynthesis is known to be high and under certain conditions, may reach 100% [3,4]. This amazing feat of nature is looked up to as an inspiration for the design, development, and upscaling of cost-effective technologies such as solar cells that would efficiently capture and store solar energy [5]. In contrast, for instance, Shockley and Quisser determined theoretically that a singlejunction solar cell has the maximum energy conversion efficiency of only 33% [1,3,6].…”

“…More recently, Asahi, Kita, and their colleagues reported a structure capable of theoretically achieving up to 63% energy conversion [7]. Hitherto, the conversion efficiency in photosynthesis is not yet fully explained thus posing a major impediment for utilizing the mechanism as a viable pathway for high-efficiency solar cells [5].…”