Related Experiment Video
Updated: Jun 17, 2026
08:29
Morphology Control for Fully Printable Organic–Inorganic Bulk-heterojunction Solar Cells Based on a Ti-alkoxide and Semiconducting Polymer
Published on: January 10, 2017
Structure, dynamics, and power conversion efficiency correlations in a new low bandgap polymer: PCBM solar cell
Jianchang Guo1, Yongye Liang, Jodi Szarko
1Chemical Science and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA.
The Journal of Physical Chemistry. B
|December 30, 2009
Summary
A new organic photovoltaic material, PTB1:PCBM, exhibits enhanced charge mobility and faster charge separation compared to P3HT:PCBM, leading to higher power conversion efficiency in solar cells without annealing.
Area of Science:
- Materials Science
- Organic Photovoltaics
- Solid-State Physics
Background:
- Bulk heterojunction (BHJ) organic photovoltaic (OPV) materials are crucial for solar energy conversion.
- Poly(thienothiophene-benzodithiophene) (PTB1) is a novel BHJ material showing promise for OPV applications.
- Understanding molecular packing and charge separation dynamics is key to optimizing OPV performance.
Purpose of the Study:
- To investigate the molecular packing structures of PTB1:PCBM films using grazing incidence X-ray scattering (GIXS).
- To analyze the photoinduced charge separation (CS) dynamics in PTB1:PCBM.
- To correlate structural and dynamic properties with the power conversion efficiency (PCE) of PTB1:PCBM based solar cells.
Main Methods:
- Grazing incidence X-ray scattering (GIXS) measurements were performed on PTB1:PCBM and P3HT:PCBM films.
- Charge mobility was measured and compared between the two material systems.
- Photoinduced charge separation rates were quantified for pristine and annealed films.
Main Results:
- PTB1:PCBM films exhibit pi-stacked polymer backbone planes oriented parallel to the substrate, unlike P3HT:PCBM.
- PTB1:PCBM shows approximately 1.7 times higher charge mobility and more than twice the CS rate compared to P3HT:PCBM.
- Annealing PTB1:PCBM films reduced PCE from 5.24% to 1.92% due to decreased interfacial area and reduced exciton generation/charge separation.
Conclusions:
- The parallel pi-stacking orientation in PTB1:PCBM contributes to enhanced charge mobility and faster charge separation.
- The combination of a small optical gap, fast CS rate, and high carrier mobility results in high PCE for PTB1:PCBM solar cells.
- Pristine PTB1:PCBM films outperform annealed films, highlighting the importance of morphology control for optimal OPV performance.
More Related Videos
Related Concept Videos
01:11P-N junction
A p-n junction is formed when p-type and n-type semiconductor materials are joined together. At the interface of the p-n junction, holes from the p-side and electrons from the n-side begin to diffuse into the opposite sides due to the concentration gradient. This diffusion of carriers leads to a region around the junction where there are no free charge carriers, known as the depletion region. The charge density within the depletion region for the n-side and p-side can be described by the...
01:12Fermi Level Dynamics
The vacuum level denotes the energy threshold required for an electron to escape from a material surface. It is usually positioned above the conduction band of a semiconductor and acts as a benchmark for comparing electron energies within various materials.
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...