Influence of defects and impurities on solar cell performance

Multicrystalline silicon (mc-Si) solar cells exhibit high impurity content and higher density of crystal defects such as grain boundaries, dislocations, stacking faults and impurity precipitates. Even though the effect of dislocations on mc-Si solar cell performance has been studied, a severe lack of understanding of the quantitative effects of dislocations on cell parameters still exists. Some correlation has been reported under the assumption of a uniform distribution of dislocation density and a negligible effect of front and back surface recombination velocity. This assumption can cause a significant error as the current mc-Si technology provides good surface passivation by SiN:H and very effective back surface fields. This work is an extension of previous models that use Green Function to include the influence of front (S_1) and back (S_2) surface recombination velocities. The three dimensional continuity equation of the minority carriers has been solved in a solar cell having periodic array of dislocations and with front and back surface recombination. Each dislocation is considered to be a space charge cylinder perpendicular to the surface and extending through the entire cell. The calculations show that low dislocation densities (< 10^4 cm^{-2}) have very little effect on the cell performance. This is in agreement with the previously published data. The results of calculated dependencies of cell parameters on the dislocation density for different recombination activities are discussed in this work.

Name thesis:degree_name

Doctor of Philosophy in Electrical Engineering - (Ph.D.)

Discipline thesis:degree_discipline

Electrical and Computer Engineering

Year

2012

Author dc:creator

• Budhraja, Vinay

Contributors dc:contributor

• Durgamadhab Misra
• N. M. Ravindra
• Bhushan L. Sopori

• Dislocations
• Modeling
• Solar cells
• Defects on solar cells
• Multicrystalline silicon
• Diode
• Electrical and Electronics

Repository record dc:identifier

https://digitalcommons.njit.edu/dissertations/294

OAI identifier oai:identifier

oai:digitalcommons.njit.edu:dissertations-1349