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The field of organic electronics continues to be driven by new charge-transporting materials that are typically processed from toxic organic solvents incompatible with biological environments. Over the past few decades, powerful examples of electrical transport as mediated through protein-based macromolecules have fueled the emerging area of organic bioelectronics. These attractive bioinspired architectures have enabled several important applications that draw on their functional electrical properties, ranging from field-effect transistors to piezoelectrics. In addition to naturally occurring protein biomacromolecules, unnatural oligopeptide self-assemblies and peptide–π conjugates also exhibit interesting electrical applications. This review provides an overview of electrical transport and electrical polarization in specialized biomaterials as manifested in solid-state device architectures.
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Probing Charge Recombination in Organic Solar Cells
Printable and flexible organic solar panels are promising sources of inexpensive, large-scale renewable energy, where panels can be manufactured by printing from polymer inks. There are some limitations to these types of solar cells, however. First, toxic halogenated solvents have historically been necessary to dissolve polymers to make the ink. In addition, organic solar cells typically have high rates of recombination, which limits their efficiency. Here, we use a transient photovoltage (TPV) technique to measure charge lifetimes in cells made from two different organic solvents. The first solvent is toxic, halogenated dichlorobenzene (DCB) which is typically used to make organic solar cells. The other is a less toxic, non-halogenated solvent, carbon disulfide (CS2). By varying the processing methods in this way, we find that cells made from CS2 have longer charge lifetimes and higher efficiencies than those made with DCB, as well as a different recombination rate order. Possible reasons for these differences are explored using simple analytic modeling. Our model indicates that while bimolecular recombination is dominant in both types of cells, those processed with DCB may have more trap-assisted recombination present than those processed with CS2. Overall, this work demonstrates that we may be able to decrease the toxicity of organic solar cell manufacturing and simultaneously improve the efficiency of the devices, bringing this powerful method of capturing solar energy to the forefront of sustainable energy solutions.
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- Award ID(s):
- 2050886
- PAR ID:
- 10611628
- Publisher / Repository:
- Macalester College
- Date Published:
- Journal Name:
- Macalester journal of physics and astronomy
- Volume:
- 12
- Issue:
- 1
- ISSN:
- 2332-7669
- Page Range / eLocation ID:
- 6
- Subject(s) / Keyword(s):
- organic solar cells, recombination, transient photovoltage
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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