Local Schottky contacts of embedded Ag nanoparticles in Al(2)o(3)SiN(x):H stacks on Si: a design to enhance field effect passivation of Si junctions

摘要

This paper describes an original design leading to the held effect passivation of Si n(+)-p junctions. Ordered Ag nanoparticle (Ag-NP) arrays with optimal size and coverage fabricated by means of nanosphere lithography and thermal evaporation, were embedded in ultrathin-Al2O3/SiNx:H stacks on the top of implanted Si n(+)-p junctions, to achieve effective surface passivation. One way to characterize surface passivation is to use photocurrent, sensitive to recombination centers. We evidenced an improvement of photocurrent by a factor of 5 with the presence of Ag NPs. Finite-difference time-domain (FDTD) simulations combining with semi-quantitative calculations demonstrated that such gain was mainly due to the enhanced held effect passivation through the depleted region associated with the Ag-NPs/Si Schottky contacts.