We report an inverse photoemission study of the unoccupied states of thin-film n-type wurtzite GaN. For incident electron energies below 30 eV, free-electron bands do not provide a good description of the initial state. However, using a calculated quasiparticle band structure for the initial state, we can obtain good agreement between our measurements and the calculated low-lying conduction bands. No evidence of unoccupied surface states is observed in the probed part of the Brillouin zone,

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... irming earlier angle resolved photoemission studies, which identified the surface states on GaN͑0001͒ as occupied dangling bond states, resonant with the valence band.