Effect of microwave annealing on amorphous Si of carbon powder

Crystalline silicon (c-Si) thin film is extremely important for low-cost, high performance Si-based devices, such as thin-film transistors and solar cells. We demonstrate that microwave irradiation onto amorphous silicon (a-Si) film on glass substrate with carbon overcoat is able to induce fast crystallization at a short annealing time, less than 300 s, 300 watt. X-ray diffraction and Raman spectroscopy were used to identify the evolution of crystallization. The reason of fast crystallization is attributed to, upon microwave irradiation, the microwave absorption of carbon overcoat to generate thermal energy, the dielectric properties of the heated a-Si, and facilitated nucleation of c-Si crystallites due to enhanced atomic vibration. The microwave crystallization of a-Si is extendable to produce c-Si on various substrates, such as plastics, on large area and remote bases.