The effect of KCN passivation on IR spectra of a-Si based structures

From the analysis of IR spectra of double layer structures after KCN passivation the presence of four absorption bands at 720–810 cm−1 (assigned as Sisingle bondC bond), 870–1060 cm−1 (assigned as Sisingle bondHn and Sisingle bondO bonds), 1930–2200 cm−1 (assigned as Sisingle bondHn bonds) and absorption band around 2360 cm−1 (assigned as Sisingle bondNCO bond) was found. As IR spectra between 1400 and 1600 cm−1 (assigned as Csingle bondH, NH2) and 3200–3300 cm−1 (assigned as Csingle bondH and Nsingle bondH) under influence of KCN passivation did not change we suggest that formation of HCN, CH and NH was eliminated (polymeric HCN). From analysis of absorption bands assigned as Sisingle bondHn, CN and SiNC (1950–2200 cm−1) and absorption bands assigned as Sisingle bondO bond (1000–1200 cm−1) it is evident the different influence of passivation on samples and . In the spectra typical features of OH group, hydrogen bridge bonding and Sisingle bondSisingle bondOCN formation were observed. From these results can be drawn the binding of CN to Si through oxygen atoms.