Raman diagnostics of free charge carriers in boron‐doped silicon nanowires

Raman spectroscopy is used to probe free charge carriers in layers of silicon nanowires (SiNWs) formed by metal‐assisted chemical etching of crystalline silicon (c‐Si) wafers followed by additional doping with boron. One‐phonon Raman spectra of the boron‐doped SiNWs are strongly modified due to the Fano effect that allowed us to determine the free carrier concentration in the nanowires in the range from 1019 to 1020 cm−3, depending on the doping conditions. The micro‐Raman mapping was used to determine the depth profile of charge carrier density along nanowires, which decreases toward the SiNWs/c‐Si interface. The obtained results are discussed in view of possible applications of the Raman spectroscopy for express‐diagnostics of doped Si nanostructures for photonics and thermoelectric applications.