Correlation of electrical, thermal and structural properties of microcrystalline silicon thin films

Thermal diffusivity (alpha) has been correlated with the electrical and structural properties of hydrogenated microcrystalline silicon (muc-Si:H) films. In the heterogeneous microcrystalline network, a and electrical conductivity (sigma(D)) maintain a one-to-one correspondence. and both these parameters are directly related to the crystalline volume fraction (F-c) of the network. For the amorphous silicon network, alpha is similar to 0.2 cm(2).s(1) and has a very low sigma(D) of similar to 10(-8) S.cm(-1). When the crystalline volume fraction (F-c) exceeds a certain percolation threshold, both alpha and sigma(D) increase abruptly. Undoped muc-Si:H films having F-c similar to 94% exhibit a high magnitude of alpha similar to 0.80 cm(2).s(-1) and a very high sigma(D) of similar to 10(-3) S.cm(-1).