Interface and material properties of wide band gap a-SiCx:H thin films for solar cell applications

Amorphous SiC Thin Films Deposited by Plasma-Enhanced Chemical Vapor Deposition for Passivation in Biomedical Devices

“…Increasing the number of C atoms breaks the Si crystalline pattern, forming C–C diamond-like bonds [ 105 ], and thus increasing the resistivity. Loulou et al’s [ 102 ] and Donercark et al’s [ 58 ] results are consistent with Du et al [ 110 ] across their respective ranges (see Figure 4 ).…”

“…Three studies [ 58 , 79 , 115 ] have examined the variation of the optical bandgap with stoichiometry ( Figure 6 ), finding a decrease in the bandgap as the Si content increases. Mastelaro et al [ 116 ] attribute the previous trend to the formation of diamond-like C–C bonds at high C content rather than to voids due to hydrogen inclusion and the formation of microvoids.…”

“…With ongoing research and improved deposition processes [ 6 , 7 , 31 , 54 , 55 , 56 , 57 , 58 ] as well as increasing opportunities for applications of a-SiC, there is now a need for a comprehensive introduction to a-SiC film optimization. To maintain a reasonable scope for the review, the main focus will be on PECVD deposition optimization as it has the most extensive literature and is most frequently used in studies on biomedical applications.…”

Surface Cleaning and Passivation Technologies for the Fabrication of High-Efficiency Silicon Heterojunction Solar Cells

“…The optical band gap of a-SiC x :H(i) can be expanded to 4 eV at high methane concentrations [79], which reduces optical absorption loss in the passivation layer [80]. However, at the a-SiC x :H(i)/c-Si interface, high interface trap density was observed with high carbon atomic concentrations [81]. Ehling et al [82] demonstrated that a low carbon content ([CH 4 ]/[(CH 4 ) + (SiH 4 )]) of 1.3% was associated with a higher lifetime value.…”

“…The resulting decrease in hydrogen atoms at the a-SiC:H(i)/c-Si interface leads to a decrease in the passivation quality [82]. Donercark et al [81] proposed the use of a stacked structure using a-Si:H(i) and a-SiC x :H(i) to improve the quality of interface passivation while ensuring that the large band gap a-SiC x :H(i) was leveraged to reduce optical absorption loss. The incorporation of carbon into a-SiC:H results in the formation of structural defects and inhomogeneities, leading to disorder in amorphous networks.…”