Oa. Williams et al., Carrier generation within the surface region of hydrogenated thin film polycrystalline diamond, DIAM RELAT, 10(3-7), 2001, pp. 423-428
Low temperature Hall effect measurements made on diamond films subjected to
a hydrogenation process, such that the near surface region becomes p-type
without the addition of conventional dopant atoms, are reported. The carrie
r concentration within the temperature range 10-300 K does not change as ex
pected for most films, actually increasing as the temperature falls. Howeve
r, polished films display more conventional behaviour in that the carrier c
oncentration falls with falling temperature. A model involving carrier tran
sport within both valance and impurity bands can be considered to explain t
hese observations, leading to the suggestion that the hydrogenation process
is capable of creating acceptor states with an activation energy within th
e range of 10-40 meV. (C) 2001 Elsevier Science B.V. All rights reserved.