Theoretical work has been carried out towards the planar (non-axial) a
nisotropy in amorphous semiconductors. The spontaneous polarization (P
-s) vector seems to move into the plane leaving the axial characters.
The work has been done in zero and non-zero electric field modes. Exis
tence of easy, hard axes and the existence of cones have been demonstr
ated. In the case of cones, P-s vector seems, under certain conditions
, to have jumps of first order giving first-order polarization (FOP).
This leads to switching mechanism of the P-s vector from a critical va
lue to saturation. This switching mechanism of the P-s vector from a c
ritical value to saturation. This switching mechanism can be predicted
as well. Some experimental evidence of internal electric fields in a-
Si:H can be demonstrated.