  In this study, a scalar field propagating in a higher-dimensional
Reissner-Nordstr\"om-de Sitter black hole is investigated. Scalar fields are
assumed to have non-minimal coupling to the brane or bulk scalar curvature.
Five different {definitions} of black hole temperatures are discussed:
temperature based on surface gravity, Bousso-Hawking temperature, and three
effective temperatures. The greybody factors of minimally and non-minimally
coupled scalar fields on the brane and in the bulk are examined under the
effect of particle and spacetime properties. The energy emission spectra of
black holes are determined at various temperatures for both the brane and bulk
channels. The energy emission rates at the Bousso-Hawking temperature are found
to be dominant over those at other temperatures. The energy emission curves are
suppressed by the presence of coupling parameters. Finally, the bulk-over-brane
emission ratios are calculated. Notably, bulk dominance becomes possible for a
certain definition of the temperatures and regime of the cosmological constant.
