  We study polarization independent improved light trapping in commercial thin
film hydrogenated amorphous silicon (a-Si:H) solar photovoltaic cells using a
three-dimensional silver array of multi-resonant nano-disk structures embedded
in a silicon nitride anti-reflection coating (ARC) to enhance optical
absorption in the intrinsic layer (i-a-Si:H) for the visible spectrum for any
polarization angle. Predicted total optical enhancement (OE) in absorption in
the i-a-Si:H for AM-1.5 solar spectrum is 18.51% as compared to the reference,
and producing a 19.65% improvement in short-circuit current density (JSC) over
11.7 mA/cm2 for a reference cell. The JSC in the nano-disk patterned solar cell
(NDPSC) was found to be higher than the commercial reference structure for any
incident angle. The NDPSC has a multi-resonant optical response for the visible
spectrum and the associated mechanism for OE in i-a-Si:H layer is excitation of
Fabry-Perot resonance facilitated by surface plasmon resonances. The
detrimental Staebler-Wronski effect (SWE) in a-Si:H solar cell can be minimized
by the additional OE in the NDPSC and self-annealing of defect states by
additional heat generation, thus likely improving the overall stabilized
characteristics of a-Si:H solar cells.
