Parasitic
absorption and limited fill factor (FF) brought in by
the use of amorphous silicon layers are efficiency-limiting challenges
for the silicon heterojunction (SHJ) solar cells. In this work, postdeposition
phosphorus (P) catalytic doping (Cat-doping) on intrinsic amorphous
silicon (a-Si:H(i)) at a low substrate temperature was carried out
and a P concentration of up to 6 × 1021 cm–3 was reached. The influences of filament temperature, substrate temperature,
and processing pressure on the P profiles were systemically studied
by secondary-ion mass spectrometry. By replacing the a-Si:H(n+er with P Cat-doping of an a-Si:H(i) layer, the passivation
quality was improved, reaching an iV
OC of 741 mV, while the parasitic absorption was reduced, leading to
an increase in J
SC by ∼1 mA/cm2. On the other hand, the open-circuit voltage and the FF of
a conventional SHJ solar cell (with the a-Si:H(n) layer) can be improved
by adding a Cat-doping process on the a-Si:H(i) layer, resulting in
an increase in FF by 4.7%abs and in efficiency by 1.5%abs.