The light-induced metastable lattice expansion in hydrogenated amorphous silicon

Nucleation mechanism of microcrystalline silicon from the amorphous phase

“…In our result, lc-Si:H nucleation was observed at $750 MPa. Similar values in a range from 750 to 1100 MPa have been reported during the phase transition from a-Si:H to lc-Si:H [16,17]. In our previous study, we further confirmed that the high compressive stress in a-Si:H enhances the formation of the SiH n complex, due to the strained Si-Si bond formation by stress [8].…”

“…4(b), we estimated N d by counting the number of lc-Si:H grains that appear in the AFM image [11]. As reported previously [16,17], the compressive stress in the a-Si:H layers increases linearly with increasing R. Nevertheless, we found that lc-Si:H nucleation occurs only when the compressive stress in the a-Si:H exceeds $750 MPa, regardless of the deposition temperatures. This shows clearly that the stress in the a-Si:H layer plays an essential role in the lc-Si:H nucleation process.…”

Light induced electrical and macroscopic changes in hydrogenated polymorphous silicon solar cells

“…As a matter of fact, there has been a great deal of research on lightinduced volume changes [50]. Various beam bending experiments have been performed using samples consisting of long and narrow pieces of thin glass or quartz substrates coated with a-Si:H [51][52][53][54][55][56][57]. These results reveal that lightinduced volume expansion follows a stretched exponential behavior, usually showing saturation at dV /V ∼ 10 −3 [29].…”

Photoinduced structural instability around the Si–H bond in undoped a-Si:H and related wide-gap alloys

“…Consulting with reported studies on the elastic properties of several kinds of undoped a-Si:H films with different hydrogen contents [13], the dilatation of an aSi:H network induced by strong light soaking [14,15], and the close correlation between the compressive stress and the hydrogen content in the monohydride configuration in undoped a-Si:H [16], it is deduced that a much stronger internal stress is induced in a disordered lattice, as more and more bonded hydrogen takes on the monohydride configuration with accompanying exclusion of inhomogeneity and an enhancement of the network rigidity. Such characteristics of the network structure correlate with that of the undoped a-Si:H with a good quality, in which the strongest modulated IR absorption is observed, as reported here.…”