Extended Data Fig. 4: Verification of reusability of sapphire substrates after 2DLT.
From: Vertical full-colour micro-LEDs via 2D materials-based layer transfer
a-b, XPS spectra of B 1s (a) and N 1s (b) regions for hBN-coated sapphire wafer (reference; black), used sapphire wafer following exfoliation of LED (LED exfol.; blue), and used sapphire wafer after removal of residual hBN layer (hBN removal; red). c-d, SEM images of blue LEDs on hBN grown on pristine (d) and reused (e) sapphire wafers.
