Correlation of the crystal orientation and electrical properties of silicon thin films on glass crystallized by line focus diode laser

• Linear grains parallel to the scan direction formed with high density.
• Σ3 coincidence lattice (CSL) boundaries found inside a grain
• Grain boundaries exhibit various CSL boundaries such as Σ9, Σ18, and Σ27.
• Grain with < 100 > orientation in normal direction showed highest electrical properties.
• Improved voltage observed when percentage of < 100 > normal orientation is increased

In this work, crystallographic orientation of polycrystalline silicon films on glass formed by continuous wave diode laser crystallization was studied. Most of the grain boundaries were coincidence lattice Σ3 twin boundaries and other types of boundaries such as, Σ6, Σ9, and Σ21 were also frequently observed. The highest photoluminescence signal and mobility were observed for a grain with (100) orientation in the normal direction. X-ray diffraction results showed the highest occupancies between 41 and 70% along the (110) orientation. However, the highest occupancies changed to (100) orientation when a 100 nm thick SiOx capping layer was applied. Suns-Voc measurement and photoluminescence showed that higher solar cell performance is obtained from the cell crystallized with the capping layer, which is suspected from increased occupancies of (100) orientation.