A detailed analysis of photovoltaic front surface phosphor-based spectral modification and light scattering by hetero-structure was conducted. Phosphor based spectral downconversion is a well known laser technology. The analysis assumes that both sunlight energy and photovoltaic performance are at peak sunlight photon flux within the spectral range. Further, the analysis presented here indicates that parasitic losses and light scattering within the spectral range are large enough to offset any expected gains. For example, analysis of up-conversion phosphor-based approaches indicates that these are likely to suffer unexpectedly large losses in the peak spectral region due to parasitic absorption when attempting to down convert UV light.