Technology ready use of single layer graphene as a transparent electrode for hybrid photovoltaic devices

摘要

Graphene has been used recently as a replacement for indium tin oxide (ITO)for the transparent electrode of an organic photovoltaic device. Due to itslimited supply, ITO is considered as a limiting factor for thecommercialization of organic solar cells. We explored the use of large-areagraphene grown on copper by chemical vapor deposition (CVD) and thentransferred to a glass substrate as an alternative transparent electrode. Thetransferred film was shown by scanning Raman spectroscopy measurements toconsist of >90% single layer graphene. Optical spectroscopy measurements showedthat the layer-transferred graphene has an optical absorbance of 1.23% at awavelength of 532 nm. We fabricated organic hybrid solar cells utilizing thismaterial as an electrode and compared their performance with ITO devicesfabricated using the same procedure. We demonstrated power conversionefficiency up to 3.98%, higher than that of the ITO device (3.86%), showingthat layer-transferred graphene promises to be a high quality, low-cost,flexible material for transparent electrodes in solar cell technology.