  Hydrogenated amorphous silicon alloy films are generally deposited by radio
frequency plasma enhanced chemical vapor deposition (RF PECVD) technique on
various types of substrates. Generally it is assumed that film quality remains
unchanged when deposited on textured or non-textured substrates. Here we
analyzed the difference in growth of thin film silicon layers when deposited in
a textured and a non-textured surface. In this investigation characteristics of
two solar cells were compared, where one cell was prepared on a textured
surface ( Cell-A) while the other prepared on a non-textured surface (Cell-B).
Defect analysis of the devices were carried out by simulation and device
modeling. It shows that the intrinsic film deposited on a textured surface was
more defective ($2.4\times 10^{17}$ cm$^{-3}$) than that deposited on a flat
surface ($3.2\times 10^{16}$ cm$^{-3}$). Although the primary differences in
these two cells were thickness of the active layer and nature of surface
texturing, the simulation results show that thin film deposited on a textured
surface may acquire an increased defect density than that deposited on a flat
surface. Lower effective flux density of $SiH_{3}$ precursors on the textured
surface can be one of the reasons for higher defect density in the film
deposited on textured surface. An Improved light coupling can be achieved by
using a thinner doped window layer. By changing the thickness from 15 nm to 3
nm, the short circuit current density increased from 16.4 mA/cm$^{2}$ to 20.96
mA/cm$^{2}$ and efficiency increased from $9.4\%$ to $12.32\%$.
