Photoluminescence quenching of WS₂ nanoflakes upon Ga ion irradiation

Modification of the electronic structure by defect engineering is crucial towards controlling the semiconductor band gap. In this report, the WS₂ nanoflakes produced by self-sustaining high temperature synthesis are irradiated by Ga ion beam. Intensities of the Raman phonon modes and the photoluminescence (PL) are decreased upon increasing dose of Ga ion beam irradiation from 2·10¹³ to 10¹⁶ cm⁻². This leads to the defect generation in the nanoflakes and their thinning. The maximum irradiation dose at 10¹⁶ cm⁻² results in the degradation of the WS₂ nanoflakes, thus to total quenching of the PL signals.