Improving organic solar cell efficiency using solution processed poly (3-hexylthiophene) buffer layer

• Published in: Micro & nano letters Vol. 14; no. 1; pp. 74 - 77
• Main Authors: Ghosekar, Ishan C, Patil, Ganesh C
• Format: Journal Article
• Language: English
• Published: Stevenage The Institution of Engineering and Technology 01.01.2019; John Wiley & Sons, Inc
• Subjects: absorbance spectrum; Buffer layers; charge carrier collection; Circuits; Current carriers; Efficiency; Energy conversion efficiency; external quantum efficiency; fullerene active layer; Fullerenes; hole transport layer; Insertion; Organic chemistry; organic solar cell; OSC efficiency; Photovoltaic cells; polymer blends; Polymers; Quantum efficiency; series resistance; Short circuit currents; Shunt resistance; Solar cells; solution processed poly(3‐hexylthiophene) buffer layer; Transport; buffer layers; OSC efficiency; fullerene active layer; polymer blends; series resistance; hole transport layer; charge carrier collection; organic solar cell; external quantum efficiency; solar cells; solution processed poly(3-hexylthiophene) buffer layer; absorbance spectrum
• ISSN: 1750-0443; 1750-0443
• DOI: 10.1049/mnl.2018.5178

In this work, it has been shown that inserting buffered poly 3-hexylthiophene layer between hole transport layer and blended polymer: fullerene active layer of the organic solar cell (OSC) improves the power conversion efficiency by 34% over the conventional OSC. The buffer layer also increases short-circuit current density from 4.97 ± 0.2 mA/cm2 (without buffer layer) to 6.12 ± 0.3 mA/cm2 (with buffer layer). These improvements are mainly due to increased absorption in the buffered polymer layer. The buffer layer insertion leads to better charge carrier collection and lesser hole recombination at the hole transport interface, which increases shunt resistance and reduces the series resistance of the device. In addition, the insertion of the buffer layer also shows significant improvement in the absorbance spectrum and external quantum efficiency of the device.