Inverted organic solar cells based on PTB7:PC70BM bulk heterojunction

This paper reports the fabrication and characterization of bulk heterojunction inverted structured organic solar cell devices (OSC) with the architecture of ITO/ZnO/PTB7:PC70BM/MoO3/Ag. The photovoltaic properties of OSC were examined through the analysis of various photovoltaic parameters, which includes the external quantum efficiency, short circuit current density (Jsc), and open circuit voltage (Voc). The inverted structured OSC device showed the efficiency of 5.87 %. The achieved efficiency can be attributed to the better light harvesting capability, improved interfacial properties and improved charge collection efficiency. The AC impedance technique was employed to extract internal parameters of the fabricated devices. The obtained impedance curves evidently exhibit high-quality correlation between the obtained data and the curve fitting data.