High Si content SRO/SiO2 bilayer superlattices with boron and phosphorus doping for next generation Si quantum dot photovoltaics

Abstract

Si quantum dots or interchangeably Si nanocrystals are promising materials for all-Si tandem solar cells in next generation photovoltaics. Si QDs in this study were fabricated by annealing sputtered Si rich oxide/SiO2 (SRO/SiO2) bilayer superlattice thin-films. Advantages of high Si content SRO layers include lower resistivity and higher light absorption cross-sections which are more suitable for photovoltaic devices. However, theoretically high Si content SRO produces greater size distribution and larger Si nanocrystals which in this case slightly lowers the bandgap towards that of crystalline Si. This study investigates the properties of high Si content SRO/SiO2 bilayer superlattice thin-films and the effect of boron and phosphorus doping.