Abstract
P-type polycrystalline silicon films were prepared by aluminum-induced crystallization and doping. The starting material was hydrogenated amorphous silicon prepared by plasma-enhanced chemical vapor deposition on glass substrates. An aluminum layer with a different thickness was evaporated on the a-Si:H. Conventional thermal annealing was performed for crystallization. X-ray diffraction and secondary ion mass spectroscopy measurements were used to study the structural change and the Al profile in the films. Resistivity, Hall mobility, carrier concentration and spectral optical transmittance were measured to evaluate the electrical and optical properties of the films. Results showed that poly-Si films could be obtained by annealing a-Si:H films at 450 to 550°C for 5 to 60 min. In spite of a relatively high oxygen impurity content in the films, they are p-type, with low resistivity, high Hall mobility and carrier concentration of 0.06 (Ω·cm), 20 cm2/Vs and ∼1018 cm-3, respectively. This technique has great potential for solar cell mass production using low-cost glass substrates.