Electrical characterization of inorganic-organic hybrid photovoltaic devices based on silicon-poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)

Abstract

Hybrid organic-inorganic photovoltaic devices based on nanostructured silicon and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hybrid devices present excellent light harvesting capabilities as well as a simple fabrication process. Unlike the metal/Si junction, PEDOT:PSS solution can be solution-casted onto the silicon surface structure to build up hybrid photovoltaic devices without using vacuum deposition techniques. Detailed electronic characterization at PEDOT:PSS/Si heterojunctions is indispensable for achieving a high-performance device. In this paper, the electronic properties of current-voltage, capacitance-voltage, and internal quantum efficiency are characterized in order to explore the organic-inorganic heterojunctions properties. The interfacial defect state density (Dit) of hybrid organic-inorganic photovoltaic devices as well as majority carrier charge transfer velocity (vn) has been extracted from the electrical measurement results. It has been found that less Dit and lower vn can lead to improved electric output characteristics of the organic-inorganic heterojunctions photovoltaic devices, which is ascribed to suppressed charge recombination at the organic-inorganic interface.