Improved stability and performance of organic photovoltaic cells by application of carbon nanostructures and PEDOT:PSS composites as additional transparent electrodes

• Published in: Solar energy Vol. 186; pp. 146 - 155
• Main Authors: Subramanyam, B.V.R.S., Mahakul, P.C., Sa, K., Raiguru, J., Alam, I., Das, S., Mondal, M., Subudhi, S., Mahanandia, P.
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 01.07.2019; Pergamon Press Inc
• Subjects: Butyric acid; Carbon nanotubes; Circuits; CNTs; Composite materials; Declination; Energy conversion efficiency; Graphene; Heterojunctions; Nanotechnology; Nanotubes; Open circuit voltage; OPVCs; Parameters; PEDOT:PSS; Photovoltaic cells; Photovoltaics; RGO; Short circuit currents; Short-circuit current; Solar energy; Stability; RGO; OPVCs; CNTs; PEDOT:PSS
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2019.04.097

•Composites of carbon nanomaterials and PEDOT:PSS prepared for transparent electrodes for OPVCs.•Improved conductivity of PEDOT:PSS due to incorporation of carbon nanomaterials.•Comparison of parameters of all solar cells under three different temperatures.•Discussion about observed stability of the devices when exposed to open atmosphere.•Composite electrode materials based solar cells performed better in all conditions. Conventional bulk heterojunction organic photovoltaic cell (OPVC) with regioregular poly[3-hexylthiophene-2,5-diyl] (P3HT): [6,6]-phenyl C61 butyric acid methyl ester (PCBM) blend as active layer has been fabricated with simple ITO/P3HT:PCBM/Al structure and its performance is compared with that of OPVC fabricated by incorporating an additional conducting layer of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) in between the active layer and ITO. An improvement of power conversion efficiency (PCE) has been observed from 2.716% to 2.733% due to the incorporation of PEDOT:PSS. The PCE has been further enhanced by replacing PEDOT:PSS with composites of carbon nanotubes (CNTs)/PEDOT:PSS and reduced graphene oxide (RGO)/PEDOT:PSS which have been prepared by simple solution method and the device parameters of all OPVCs are collated. A maximum PCE of 2.823% with corresponding short-circuit current density (Jsc) of 9.858 mA/cm2, open-circuit voltage (Voc) of 646.923 mV, and a fill factor (FF) of 44.263% has been achieved (at 25 °C) for the device with 5 wt% of CNTs in PEDOT:PSS. The performances of all fabricated OPVCs have been compared at different temperatures (25 °C, 30 °C, and 35 °C) and a declination in PCE is noted with increase in temperature. The stability of selected devices exposed to open atmosphere has been checked by measuring their parameters at different time intervals and it is observed that the degradation of materials reduces the performance of OPVCs. Under all different circumstances, OPVCs fabricated using the composites have been observed to perform better along with significant enhancement in PCE compared to OPVCs fabricated without using the composites.