Accelerated potential-induced degradation technology for crystalline silicon cells

Potential-induced degradation (PID) is recently recognized as one of the most important degradation mechanisms in crystalline silicon cells as well as in photovoltaic (PV) modules. The ability of solar cells to resist PID effect is one of the key indicators of product quality monitoring. Traditional PID testing methods are complex and require up to 96 h in treating. To accelerate the PID test, a rapid PID treatment technology was urgent for PV field, which can extremely decrease the time expense. Hence, we have introduced a novel rapid PID treating technology, which reduced the treatment time from nearly 100 h to less than 8 h. This technology was applying an electric field directly on the solar cells to simulate the PID process of the modules. The process was named as electric field treatment (EFT). The effect of the applied EFT voltage on the solar cells was investigated from 1 to 1.8 KV. The degradation rate of the solar cells increased with increase in EFT voltage. The result of the energy dispersive spectrometer showed that the sodium element was found in the shunt area of the cell. It indicated that the microscopic principle of the power loss of the cell caused by the EFT was in accordance with that of the traditional PID. The electric performances of the cells treated by EFT showed that the PID test time can be accelerated to less than 8 h.