RGO integrated MEHPPV and P3HT polymer blends for bulk hetero junction solar cells: A comparative insight

Abstract

In this paper, a comparative study of reduced graphene oxide (rGO) integrated with poly[2-methoxy,5-(2′-ethylhexyloxy)-p-phenylenevinylene] (MEHPPV) and poly(3-hexylthiophene) (P3HT) conducting polymers have been conducted in order to obtain an efficient active layer material for organic photovoltaic (OPV) device fabrication. The structural and morphological properties have been investigated using techniques such as X-ray diffraction, field emission scanning electron microscopy, thermogravimetric analysis, and Raman spectroscopy. The optical and electrical characterizations have been performed to explore the photoluminescence quenching behaviour, electron transfer properties and efficient energy conversion. Moreover, the quantification of charge transport properties was estimated using Stern-Volmer and modified Stern-Volmer plots. The quenching constants obtained for MEHPPV–rGO nanocomposite was 2.41 × 103 L−1 and 2.72 × 103 L−1 for P3HT–rGO nanocomposite to better charge transfer capabilities found in nanocomposites. Further, the contact angle and surface energy measurement studies conducted on thin films also proposed that P3HT-rGO nanocomposite pairs are more suitable for solar cell applications as compared to MEHPPV- rGO. However, the I-V results obtained from the fabricated devices indicate that the rGO composites blended with P3HT polymer showed an efficiency of 0.045% while those composed with MEHPPV shows only 0.024%.