The nc-Si films with controlled crystal structure and electrical conductivity via the re-crystallization approach

Nanocrystalline silicon (nc-Si) films were synthesized via different re-crystallization approaches from amorphous silicon (α-Si:H) films deposited using plasma enhanced chemical vapor deposition (PECVD). The microstructure evolution with various annealing conditions was investigated via high resolution transmission electron microscopy (HRTEM) and Raman spectrometry. It was found that, compared with the conventional solid phase crystallization (SPC) annealing, a rapid thermal process (RTP) pre-annealing at 600 °C for 60 s can significantly enhance the recrystallization process and the electrical conductivity of nc-Si films. In addition, for the nc-Si films with similar crystal sizes, it was uncovered that the logarithm of conductivity presented a linear relationship with the crystalline volume fraction. This study has therefore been an important step forward to the future synthesis of the nc-Si films with manipulated microstructure and electrical conductivity for further applications.