Interface properties of ITO/n-Si heterojunction solar cell: Quantum tunneling, passivation and hole-selective contacts

Abstract

In this report, a numerical simulation for ITO/n-Si based hetero-junction (ISHJ) photovoltaic device has been carried out by using AFORS-HET software and a proper model, in which the naturally derived interface layer with a ternary-like hybrid of a-SiOx(In) is assumed to be a double stacks of 1.2 nm quasi p type semiconductor and 0.2 nm insulator as buffer layer. The negative charge centers, in the range of >1 × 1017 cm−3, associated with oxygen vacancies and indium-ion correlative ternary hybrid in the intermediate region play multi-roles, including field effect passivation, inducing inversion layer and acting selective contacts to a certain extent. The simulation results manifest that the intermediate region behaviors as a semiconductor material with a wide band gap of 2.06 eV, which is suitable for the transport of hole and an induced quasi p-n junction. Additionally, the simulated J-V curve arisen from the key opto-electric parameters of the device by the simulation agrees with the experimental one with a high fill factor of 74.2% well.