Corona Charge in SiO2: Kinetics and Surface Passivation for High Efficiency Silicon Solar Cells

Abstract

This manuscript presents a method by which capacitance-voltage measurements can be used in conjunction with Kelvin-probe measurements to calculate the location of charge within a dielectric layer. A first order kinetic model for the transport of charge into SiO2 films after exposure to corona charge deposition is proposed. The rate limiting step for charge migration into oxide films has been observed to be the injection of charge from the surface (air-SiO2 interface). The charge lies preferentially at the air-SiO2 and SiO2-Si interfaces, and its injection into SiO2 has been characterized as having an activation energy of ∼ 50 meV. In this work, corona charge deposition has produced SRV < 2.7cm/s and J01 < 12 fA/cm2 which is within the requirements of high efficiency silicon solar cells. These results contribute to the understanding of corona charge interaction with SiO2 with a view to its potential application as an extrinsic method of passivation for highly efficient silicon solar cells.