Electrical
properties of transparent conductive ZnO:B films, obtained
by the low-pressure metal organic chemical vapor deposition (LP-MOCVD)
technique, were monitored during the given time, and a heavy worsening
of these properties was observed. At the same time, other ZnO:B samples
subjected to a post-deposition treatment by argon plasma etching showed
an appreciable enhancement of the electrical stability in the given
time. A degradation mechanism, involving formation of O– adsorbate and its diffusion inside the grain boundary, is proposed
as responsible of the carrier mobility worsening. Furthermore, the
beneficial effect of the plasma treatment is explained in terms of
a rearrangement of the grain boundary with a decrease of positively
charged defect density and, consequently, a slowing down of O– formation rate. Finally, argon plasma post-deposition
treatment is proposed as an effective process for obtaining ZnO:B
films with an appreciable electrical stability in the given time.