Performance improved by point-contact electrodes and SiO sub( 2)/SiN sub( X) layers at rear

The rear point-contact fabricated through the laser-opening technique for mass production was applied on the photovoltaic cells. Laser opening, different layers for passivation (SiO sub( 2)) and protection (SiN sub( X)) were employed to investigate their impact on the performances of solar cells. The SiN sub( X) layer protects the SiO sub( 2) layer from being burnt through by aluminium paste at the co-firing step. A conversion efficiency ( eta ) of 16.91% with an open-circuit voltage of 628 mV was obtained for the optimal cell, a stack structure with SiO sub( 2) and SiN sub( X) layers, which also achieves a lower contact resistance of 6.66 m Omega .cm super( 2) and a higher light-beam-induced current of 80.77 mA/cm super( 2). The optimal cell also showed longer lifetime and 3%-4% increased quantum efficiency in the visible wavelength range. Therefore, the developed process has simplicity and reliability, fast and cost-effective and could be applied to industrial applications.