The behavior of impurity copper in n- and p-type InP has been studied.
It is concluded from Hall measurements, optical absorption spectra, a
nd the results of isothermal annealing that the electrical activity of
copper is amphoteric. A donor level with an energy E(upsilon) + 0.1 e
V is observed; this level is linked with interstitial copper. An inter
pretation of this level is proposed.