Abstract
The authors report that for
a
-
Si
:
H
∕
c
-
Si
heterostructure solar cell fabrication the presence of a boron-doped
a
-
Si
:
H
(
p
+
)
overlayer may cause
H
2
effusion from a (few nanometers) thin underlying intrinsic
a
-
Si
:
H
(
i
)
film at moderate temperatures. This phenomenon is in agreement with losses in the electronic passivation quality of
c
-
Si
∕
a
-
Si
:
H
(
i
)
∕
a
-
Si
:
H
(
p
+
)
structures occurring during low temperature
(
⩽
260
°
C
)
postdeposition annealing. Consequently, it is argued that such passivation degradation is due to Si-H rupture in the
a
-
Si
:
H
(
i
)
film, likely resulting in Si dangling bond defects, mediated by the presence of the doped layer.