Research Grants/Fellowships/SBIR

Manufacture of Photovoltaic Solar Cell Using Plant Chlorophyll

EPA Grant Number: SU833536
Title: Manufacture of Photovoltaic Solar Cell Using Plant Chlorophyll
Investigators: Gao, Ning , Carr, Reed , Rosales, Jon
Current Investigators: Gao, Ning , Carr, Reed , Holland, Camden , Kozlowski, Andrew , Lenanyokie, Alice , Rosales, Jon , Webster, Caroline
Institution: St Lawrence University
EPA Project Officer: Nolt-Helms, Cynthia
Project Period: August 30, 2007 through August 29, 2008
Project Amount: $8,089
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2007) RFA Text |  Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Energy , P3 Awards , Sustainability



The need for renewable energy is a global concern, due to increasing energy consumption patterns worldwide and the inevitable depletion of the world’s oil reserves. Because of the demand for a cheap, efficient, clean, and renewable energy source, photovoltaic (PV) cells have emerged as a viable energy source, and a promising material for their manufacture is chlorophyll. Chlorophyll-based (organic) PV cells show great potential for developing widely available and practical non-fossil fuel-based energy. These organic solar cells operate on the same principle as the familiar silicon cells. However, instead of being manufactured at high temperatures (1900°C), organic PV cells are fabricated using less-expensive carbon-based compounds at room temperature. We propose to study the viability of producing chlorophyll-based solar cells as a supplement to ‘grid’ electricity.

Initially, we will build on the pioneering work of Aoki et al. at Otia University in Japan. Their study tested chlorophyll a with 4-imidazole-acetic acid (Im) as an axial ligand (MgChl-a-Im) absorbed on a nanocrystalline TiO2 film (MgChl-a-Im/TiO2) electrode as a photosensitizer in the visible region. Our project will extend their work, first by using extracted chlorophyll from spinach for preliminary trials. Once we have shown the reaction works as planned, we will expand the process and use purchased chlorophyll. Another cell will be prepared from a mixture of chlorophyll a and chlorophyll b. The absorbed wavelengths of light absorbed by the organic PV cells will be analyzed using spectroscopy and then compared. The purpose will be to determine the amount of light absorbed by each cell by measuring the amount of incident light absorbed. The ultimate goal of the project is to develop a production methodology for a chlorophyll-based Graetzel cell that is more efficient than the one developed by Aoki et al.

As a possible extension beyond this project, the effect of the central coordinated atom could be investigated by substituting the Mg atom in chlorophyll with other metals such as calcium and scandium to determine if better properties may be obtained. The high cost of manufacturing silicon-based photovoltaics (cost/watt) has been an obstacle to widespread adoption. Nonetheless, the use of PV cells has been growing at a rate of 25–30% over the past several years. A simplified process for producing chlorophyll-based PV cells could result in an increased number of entrepreneurial startups, especially in remote areas which there is need for off-the-grid energy. Reducing costs and increasing volume output would lower the price of each cell, making it a reasonable alternative to silicon-based solar cells. The development of practical organic solar cells would lower the world-wide demand for fossil fuels and deliver humanitarian benefits. The proposed work will also contribute to the ongoing effort of St. Lawrence University to use P3 Concepts as an educational tool.

Supplemental Keywords:

RFA, Air, climate change, Air Pollution Effects, Atmosphere

Progress and Final Reports:
Final Report