Utilization of ultra-thin n-type Hydrogenated Nanocrystalline Silicon for Silicon Heterojunction Solar Cells

To optimize the electrical performance of silicon heterojunction solar cell devices, the electronic properties and microstructure of n-type nc-Si:H were characterized and analyzed. It was found that higher conductivity and crystalline volume fraction (F
c
) of nc-Si:H can be obtained at lower silane gas fraction (f
SiH4
), lower power and higher phosphorous gas fraction (f
PH3
). In our case, there is a decline of the passivation for the devices with nc-Si:H after sputtering process. By increasing the phosphine flow fraction, the sputter damage can be reduced and 3%
abs
gain of FF as well as 0.7%
abs
gain of efficiency is reached compared with reference. The best solar cell exhibits the V
oc
of 733.3 mV, FF of 79.7%, J
sc
of 39.00 mA/cm
²
and η of 22.79% at the M2 size wafer.