| Summary: | 碩士 === 國立成功大學 === 機械工程學系碩博士班 === 101 === In the present study, 15 kinds of the a-Si/Al/a-Si/SiO2/Glass specimen were prepared in order to investigate the Al-induced Si crystallizations after applying annealing. The composite film of a-Si/Al/a-Si is arranged in the sandwich form in order to improve the efficiency of Al diffusions into its two adjacent Si layers, and thus resulting in the increase in the specimen’s carrier mobility. Si crystallizations were carried out at the conditions including the changes in the thicknesses of the top and bottom Si layer and the middle Al film, and the annealing temperature. Al diffusion depths on its two sides is increased with increasing the max compressive stress change in the diffusion direction. The degree of Si crystallizations in terms of the product (PC) of the Si crystalline fraction and the mean grain size. The PC value is elevated by increasing the ( ), and specimen’s carrier mobility is linearly increased by increasing ( ). In the specimens without nanovoids, the ( ) value is presented to be increased proportional to . A sufficiently high annealing temperature in combination with sufficiently large become the prerequisite conditions of nanovoids created in the composite film. The increases in the ( ) leads to the reduction of R* value, thus resulting in the elevation of specimen’s carrier mobility. Appropriate thickness designs for the sandwich structure can achieve high Si crystallizations even operating the annealing process as low as 400 °C. High-quality poly-Si is an essential material for high-efficiency thin-film solar cells or AMOLED.
|
|---|
