| Popis: |
Using highly hydrogen diluted silane as the reaction gas which was resolved with r.f. + d.c. double power sources, we have fabricated the nano-crystallite silicon (nc-Si) films. Based on the interfacial trap theory of poly-Si and revised by small size effect, we have got the relationship between conductivity of nc-Si films and defect levels in its interfacial region. Photoabsorption spectra and conductivity of nc-Si have been measured at low temperatures from 4.2 K to 77 K. According to theoretical analyses and experimental results, we suggest that the temperature behavior of the conductivity of nc-Si film is exponential at low temperature; the defect levels which are induced by interfaces are deep levels. Photoconduction experiments show that the carrier lifetime of nc-Si is as high as 10 ms, and the trap effects are very strong. |
