Fig. 4

a Visible-reflected (VIS); b UV-induced visible luminescence (UVL); c Infrared-reflected false colour (IRRFC); d UV-reflected false colour (UVRFC); e Visible-induced visible luminescence (VIVL) images of the front of F1

a Visible-reflected (VIS); b UV-induced visible luminescence (UVL); c Infrared-reflected false colour (IRRFC); d UV-reflected false colour (UVRFC); e Visible-induced visible luminescence (VIVL) images of the front of F1