Reflectance
measurements
in the visible region (400–800 nm) were recorded on BSi samples
using a Lambda 650S spectrometer (Perkin Elmer) equipped with an integrating
sphere. The spectra resolution of the instrument is 0.17 nm, and the
measurements were recorded with a 1 nm step.
Angle-resolved
reflectivity measurements were carried out using a custom-built 2θ
system, as shown inFigure S12 . The system
consisted of a Thorlabs halogen lamp weakly focused onto a sample
positioned on the inner stage of the rotating 2θ system. The
reflected light was collected by means of a collection lens and optical
fiber mounted on the outer stage of the system, which rotated at twice
the rate of the inner stage. The fiber was connected to an Ocean Optics
USB4000 visible range spectrometer with a spectral resolution of 0.2
nm. The measurements were carried out with an angular step of 0.5°
and for the wavelength range 400–750 nm (where applicable,
values are reported as average value ±1 s, where s stands for sample standard deviation).
measurements
in the visible region (400–800 nm) were recorded on BSi samples
using a Lambda 650S spectrometer (Perkin Elmer) equipped with an integrating
sphere. The spectra resolution of the instrument is 0.17 nm, and the
measurements were recorded with a 1 nm step.
Angle-resolved
reflectivity measurements were carried out using a custom-built 2θ
system, as shown in
consisted of a Thorlabs halogen lamp weakly focused onto a sample
positioned on the inner stage of the rotating 2θ system. The
reflected light was collected by means of a collection lens and optical
fiber mounted on the outer stage of the system, which rotated at twice
the rate of the inner stage. The fiber was connected to an Ocean Optics
USB4000 visible range spectrometer with a spectral resolution of 0.2
nm. The measurements were carried out with an angular step of 0.5°
and for the wavelength range 400–750 nm (where applicable,
values are reported as average value ±1 s, where s stands for sample standard deviation).