Bulk Heterojunction Solar Cells: Morphology and Performance Relationships
Ye Huang †‡, Edward J. Kramer *‡§, Alan J. Heeger *, and Guillermo C. Bazan *†
†Center for Polymers and Organic Solids, Department of Chemistry & Biochemistry, ‡Department of Materials, §Department of Chemical Engineering, and Department of Physics, University of California, Santa Barbara, California 93106, United States
DOI: 10.1021/cr400353v
Publication Date (Web): May 28, 2014
Table of Contents
1. Introduction
2. Characterization Tools for Morphology Study
2.1. Grazing Incidence Wide-Angle X-ray Scattering (GIWAXS)
2.2. Grazing Incidence Small-Angle X-ray Scattering (GISAXS)
2.3. Resonant Soft X-ray Scattering (R-SoXS)
2.4. Small-Angle Neutron Scattering (SANS)
2.5. Transmission Electron Microscopy
2.6. Atomic Force Microscopy (AFM)
2.7. Solid-State Nuclear Magnetic Resonance (NMR)
2.8. Dynamic Secondary Ion Mass Spectrometry (DSIMS)
2.9. Near-Edge X-ray Absorption Fine Structure (NEXAFS)
2.10. Scanning Transmission X-ray Microscopy (STXM)
3. Morphology and Performance Relationships
3.1. Physical Methods
3.1.1. Solvents
3.1.2. Thermal Annealing and Postannealing
3.1.3. Solvent Annealing
3.1.4. Polar Solvent Effect
3.1.5. Donor:Acceptor Ratio
3.2. Chemical Modifications
3.2.1. Main Chain
3.2.2. Side Chain
3.2.3. Molecular Weight
4. Summary and Outlook
With the hope of solving the present energy crisis and associated environmental issues, much research has been focused on solar cells that can harvest energy directly from sunlight to enable sustainable and green energy technology. Organic photovoltaic thin fi lms o ff er considerable promise for meeting some of these needs. Their potential for low-cost and fast roll-to-roll production as well as their light weight and fabrication on fl exible substrates could give them major advantages over traditional inorganic solar cells. |