Electronic transport and optical properties of microcrystalline Si prepared
by plasma enhanced chemical vapor deposition are discussed in terms of eff
ective medium approximation (EMA). The electrical conductivity and the Hall
mobility as a function of volume fraction of crystalline are replicated we
ll by the EMA calculation with a percolation threshold at 33% crystalline v
olume fraction. The well known excess optical absorption in fundamental abs
orption region can be also explained by the EMA. The Hall mobility is subli
nearly proportional to the size of crystallites when the volume fraction of
crystallite is kept the same, which is attributed to a fractal property of
microcrystalline system. (C) 2000 Elsevier Science B.V. All rights reserve
d.