Microcrystalline-silicon-oxide-based N-type reflector structure in micromorph tandem solar cells

Abstract

N-type microcrystalline silicon oxide thin films (n-μc-SiO x:H) have been deposited by VHF-PECVD (40MHz) with reactant gas mixtures of CO2/SiH4 and H2. N-c-SiOx thin films exhibiting low refractive index value (n 600nm ∼2), and medium/high conductivity (> 10-9 S/cm) are suitable to be used as an n-type reflector in micromorph tandem solar cells. Transmission electron microscopy (TEM) results show that microstructures of n-c-SiOx:H thin films contain nanocrystalline Si particles, which are randomly embedded in the a-SiOx matrix. This specific microstructure provides n-c-SiO x:H thin films excellent optoelectronic properties; therefore, n- c-SiOx:H thin films are appropriate candidates for n-type reflector structures in Si tandem solar cells. Copyright © 2012 Chiung-Nan Li et al.