High-temperature laser annealing for thin film polycrystalline silicon solar cell on glass substrate

Thin film polycrystalline silicon films grown on glass substrate were irradiated with an infrared continuous wave laser for defects annealing and/or dopants activation. The samples were uniformly scanned using an attachment with the laser system. Substrate temperature, scan speed and laser power were varied to find suitable laser annealing conditions. The Raman spectroscopy and Suns-V c analysis were carried out to qualify the films quality after laser annealing. A maximum enhancement of the open circuit voltage V c of about 100 mV is obtained after laser annealing of as-grown polysilicon structures. A strong correlation was found between the full width half maximum of the Si crystalline peak and V c. It is interpreted as due to defects annealing as well as to dopants activation in the absorbing silicon layer. The maximum V c reached is 485 mV after laser treatment and plasma hydrogenation, thanks to defects passivation