1 Correction to: Journal of the Korean Physical Society (2021) 78:810–815 https://doi.org/10.1007/s40042-021-00145-8

Due to an unfortunate oversight the position of "EF (0.5 h)" and "EF (48 h)" is given incorrectly. It should read:

Fig. 4
figure a

a UPS spectra of the SEC region of ITO kept for 0.5 and 48 h in the entry chamber. b Energy-level diagram of ITO and NPB. Evac, EF, WF, LUMO, HOMO, EA, and IE denote the vacuum level, Fermi level, work function, lowest-unoccupied molecular orbital, highest-occupied molecular orbital, electron affinity, and ionization energy, respectively