Effect of low temperature synthesis of carbon nanotube nanocomposite on the photovoltaic performance of anode buffer layer in polymer solar cells

Abstract

Today's solar cells are simply not efficient enough and are currently too expensive to manufacture for large-scale electricity generation. However, potential advancements in nanotechnology may open the door to the production of cheaper and slightly more efficient solar cells. This research is based on the study of photovoltaic properties of low temperature synthesized carbon nanotube (CNT) nanocomposite as an anode buffer layer for the PEDOT:PSS based polymer solar cells. CNT was synthesized using simple and cost effective method at low temperature. The structural and optical properties of prepared CNT samples were characterized using X-ray diffraction (XRD) analysis, Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM) and UV spectroscopy. CNT/PEDOT:PSS nanocomposite solutions was prepared and spin coated on a cleaned glass substrate at different spin coating speed, the fabricated buffer layer thin film devices were annealed from 100 °C to 500 °C, their optical and electrical properties were then analyzed. The XRD of synthesized CNTs nanoparticles show diffraction pattern which exhibit tetragonal structure and FTIR shows functional group of carbon nanotube. The SEM image showed that the obtained sample maintained tubular structure, cluster at 20 nm but properly dispersed at 100 nm. The optical studies of the films show an increase in absorbance as the annealing temperature increases. The photovoltaic performance of the polymer solar cell showed an improved efficiency of 6.44 % for optimized device. It is deduced from this work that low temperature synthesized CNT nanocomposite demonstrated better performance as anode buffer layer for high efficient polymer solar cells.