Enhanced performance of silicon solar cells by application of low-cost sol–gel-derived Al-rich ZnO film

• An analysis was made for some parameters of PERC and standard solar cells.
• The diffusion length value was enhanced to ∼571 μm from ∼218 μm.
• Improvement in Jsc and Voc values of PERC solar cell was ∼2.94 and ∼2.61% respectively.
• The effective back surface recombination velocity of PERC solar cell was ∼67 cm/s.
• The enhancement in relative conversion efficiency was ∼4.73%.

Sol–gel-derived hydrogen-annealed Al-rich zinc oxide (AZO) film has been investigated as an effective passivating layer on p-type silicon. In this paper, silicon nitride (SiNx) film is used as antireflection coating and passivating layers on a phosphorous diffused n+-front emitter, whereas sol–gel-derived hydrogen-annealed AZO film is used as a passivating and capping layer on the p-back surface of PERC (passivated emitter and rear cell with local Al back surface field) structure-based mono-crystalline (c-Si) solar cells to evaluate the potential of the AZO film. The illuminated J–V characteristics and internal quantum efficiency (IQE) of PERC and standard (conventional, full area Al back surface field) solar cells have been measured for comparison. The IQE data was used to determine the effective diffusion lengths of the solar cells, which were found to be 218.09 ± 4.36 and 571.13 ± 11.42 μm for standard and PERC solar cells, respectively. The effective back surface recombination velocity of the PERC solar cell was found to be ∼67 cm/s with a metal coverage area of 12%, which is lower than the back surface recombination velocity (∼451 cm/s) of the standard solar cell. The achieved conversion efficiencies of the standard and PERC solar cells were 14.31 ± 0.08% and 15.16 ± 0.09%, respectively.

A study of passivation properties of aluminum rich zinc oxide (AZO) film and its application in PERC solar cells. The diffusion length of PERC (AZO passivating layer with Al local BSF) solar cells enhanced to a value of 571.13 ± 11.42 μm in comparison with of standard (Al BSF on full area) solar cells (218.09 ± 4.36 μm). Improvements in Jsc and Voc values of PERC solar cell are found to be ∼2.94% and ∼2.61% respectively. The effective back surface recombination velocity of PERC solar cell is found to be ∼67 cm/s. The achieved conversion efficiencies of standard and PERC solar cells are 14.31 ± 0.08 and 15.16 ± 0.09% respectively.Figure optionsDownload as PowerPoint slide