Grantee Research Project Results
Don't Eat Your Spinach: Nature Inspired Biohybrid Solar Cells
EPA Grant Number: SU835287Title: Don't Eat Your Spinach: Nature Inspired Biohybrid Solar Cells
Investigators: Jennings, G. Kane , Anilkumar, Amrutur V.
Institution: Vanderbilt University
EPA Project Officer: Hahn, Intaek
Phase: II
Project Period: August 15, 2012 through August 14, 2014 (Extended to August 14, 2015)
Project Amount: $88,992
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2012) Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Air Quality , P3 Challenge Area - Chemical Safety , Pollution Prevention/Sustainable Development , Sustainable and Healthy Communities
Objective:
Our team will work to design and develop solar panels where the active components for solar conversion are nanoscale photosynthetic proteins (Photosystem I (PSI)) harvested from spinach and other green plants. In Phase II, we propose to build both on the scale up strategies our design team developed in Phase I and also a new result from the research team, to scale up a second generation biohybrid solar cell that promises to yield greatly enhanced solar conversion performance.
Approach:
First, we will extract PSI from other sources beyond spinach, including rapidly growing, non-food-based plants such as kudzu. Developing PSI films from a non-food plant would lessen any impact that biohybrid solar cells, assuming an ultimate large-scale production, would have on food supply. Second, we will optimize the PSI film thickness to maximize power generation on the new substrates. In general, thicker PSI films provide greater photocurrents because they absorb more of the incoming light, until a critical thickness is reached when light can no longer penetrate the film and reach the underlying substrate. Third, we will identify the most effective mediator for this new PSI/semiconductor system and fine tune its concentration. The mediator must accept electrons from PSI at a sufficiently high potential that it can rapidly deliver those electrons to a counter electrode. Fourth, we will investigate whether conductive additives within the PSI film aid in electron transfer and overall photocurrent output. The system of chlorophyll molecules surrounding each PSI protein provides some conductivity within the PSI films for rapidly transferring electrons, but boosting this transfer rate through additives could greatly enhance photocurrents and efficiencies. Fifth, we must scale up the individual cell to modules and panels. This scale up will be guided by the cell/module/panel assembly strategies developed in Phase I but applied to a different cell design.
Expected Results:
We have very recently demonstrated 850 μA/cm2 photocurrent densities from our PSI films by swapping the gold electrode with an appropriate semiconductor. This current density is ~400-fold larger than that produced by our first-generation cell that has spurred this Phase I project and is larger than any photocurrent ever reported for PSI-based systems, pushing toward the mA/cm2 range that is typical of mature silicon-based photovoltaics. Successful scaleup of this technology would amplify our power over previous devices.
Publications and Presentations:
Publications have been submitted on this project: View all 4 publications for this projectJournal Articles:
Journal Articles have been submitted on this project: View all 4 journal articles for this projectSupplemental Keywords:
photosynthesis, photoelectrochemical, siliconRelevant Websites:
Phase 1 AbstractProgress and Final Reports:
P3 Phase I:
Don’t Eat Your Spinach: Nature Inspired Biohybrid Solar Cells | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.