A structure corresponding to the n = 1, 2, and 3 free-exciton states i
s observed in the optical transmission spectra of zinc diarsenide at 5
K. The band gap for E perpendicular to C at temperatures of 5-300 K a
nd the exciton binding energy (17.5 eV) are determined. (C) 1998 Ameri
can Institute of Physics.