Self-assembled nc-Si-QD/a-SiC thin films from planar ICP-CVD plasma without H₂-dilution: a combination of wide optical gap, high conductivity and preferred 〈220〉 crystallographic orientation, uniquely appropriate for nc-Si solar cells

Abstract

Spontaneous miniaturization and rapid synthesis of self-assembled nc-Si-QDs of 〈220〉 orientation in high crystalline nc-Si-QD/a-SiC thin films of high conductivity and wide optical gap is obtained in ICP-CVD, from (SiH4 + CH4)-plasma, without H2-dilution.

Influence of band gap of p-type hydrogenated nanocrystalline silicon layer on the short-circuit current density in thin-film silicon solar cells

“…3, which indicates that J sc increased to maximum (13.08 mA/cm 2 ) with E g = 1.91 eV and then dropped to 12.47 mA/cm 2 with E g increased further. This seems different from the simulation result of J sc versus optical gap of the a-SiC:H p-layers [10] . However, we noted that Hou et al [23] and Liu et al [24] also reported similar dependence of J sc on E g (the 1st to 3rd column of Table 2).…”

“…The E g of "window" p-layer could be increased by alloying with additional elements such as C and O. The alloys such as amorphous hydrogenated silicon carbide (a-SiC:H) [7,8] and amorphous silicon oxide (a-SiO:H) [9] provided wide E g and enabled high V oc above 1 V. However, the electrical conductivity of the a-SiC:H or a-SiO:H p-layer would become poorer if the gaps were opened further [10,11] . Nanocrystalline or protocrystalline film could be a better alternative due to its wide gap and high electrical conductivity.…”