Effect of a silicon nitride film on the potential-induced degradation of n-type front-emitter crystalline silicon photovoltaic modules

We investigate the effect of silicon nitride (SiN_x) films in n-type front-emitter (n-FE) crystalline Si (c-Si) solar cells on the potential-induced degradation (PID) of n-FE photovoltaic (PV) modules. A negative-bias PID test for a few min does not degrade the performance of PV modules with n-FE cells without SiN_x/silicon dioxide (SiO_2) stacks, unlike in the case of PV modules with cells with SiN_x/SiO_2. This is because of the absence of polarization-type PID. After a longer PID test, the PV modules with n-FE cells without SiN_x/SiO_2 show a slower decrease in fill factor (FF), originating from Na introduction into the depletion layer of a p–n junction, than the modules with cells with SiN_x/SiO_2. The mitigation of PID by eliminating SiN_x is partly consistent with the results of PV modules with p-type conventional cells without SiN_x in which no PID occurs. SiN_x thus has a function of enhancing Na introduction into c-Si.
identifier:https://dspace.jaist.ac.jp/dspace/handle/10119/18016