1. Incorporating semiconducting single-walled carbon nanotubes as efficient charge extractors in organic solar cells.
- Author
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Abeygunasekara, Waranatha L., Hiralal, Pritesh, Samaranayake, Lilantha, Chih-Tao Chien, Kumar, Abhishek, Flewitt, Andrew J., Karunaratne, Veranja, and Amaratunga, Gehan A. J.
- Subjects
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SOLAR cells , *SINGLE walled carbon nanotubes , *SEMICONDUCTORS , *EXTRACTION apparatus , *ENERGY conversion - Abstract
We report on the improvement of power conversion efficiency (PCE) of PTB7/PC70BM solar cells by the addition of small quantities (0.02%-0.04%) of pristine single-walled carbon nanotubes (SWNTs) in the active-layer. SWNTs and purified semiconducting SWNTs (S-SWNTs) were added in quantities, which is 2 orders of magnitude lower than previously reported value and resulted in a reduction in the series resistance of the solar cell with minor changes on the shunt resistance. On addition of purified S-SWNT, the PCE of air measured devices enhanced by 29% from 4.9% to 6.3%, with short-circuit current density (JSC) improving from 12.1mA/cm² to 14.4 mA/cm² and a fill factor improvement from 54% to 61%. In addition, the role of processing additive N-Methyl-2-pyrrolidone, which acts as a SWNT dispersant, is also investigated. A single diode model of a solar cell is used to extract the cell parameters and understand the effect of SWNTs. Based on experimental data and it's fitting to the single diode model, we propose that S-SWNT improve the transport and extraction of photogenerated charges within the solar cell device. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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