Charge transport in hydrogenated boron-doped nanocrystalline silicon-silicon carbide alloys

Abstract

We have investigated the carrier transport mechanism of mixed-phased hydrogenated boron-doped nanocrystalline silicon-silicon carbide alloy ͑p-nc-Si-SiC: H͒ films. From temperature-dependent dark conductivity measurements, we found that the p-nc-Si-SiC: H alloys have two different carrier transport mechanisms: one is the thermally activated hopping between neighboring crystallites near the room-temperature region and the other is the band tail hopping below 150 K.

Influence of the statistical shift of Fermi level on the conductivity behavior in microcrystalline silicon

“…Another sample (B 2 H 6 /SiH 4 = 8000ppm and crystalline volume fraction = 22.8%) lies in the intermediate region, while rest of the samples have values well within the anti MNR region, and it is the transition region between these two extremes which has been reported in the Ref. [53].…”

“…Now we consider the case#5 [ Fig. 3 (b), Myong et al 53,54 ] which shows the data of hydrogenated boron (B)-doped nc-Si-SiC:H (p-nc-Si-SiC:H alloy) material. This is similar to the µc-Si,C alloy material mentioned in Ref.…”

“…In the doping series, σ d is reported to follow MNR with a very high value of E MN (≈295 meV), which has been explained by thermally activated hopping between neighboring crystallites dominating the carrier transport in T >150 K regime. 53 The possibility of extended-state transport was ruled out in the study. 53 The dilution series has not been studied for MNR behavior in this work.…”

“…53 The possibility of extended-state transport was ruled out in the study. 53 The dilution series has not been studied for MNR behavior in this work. 54 When we plot together the data of samples of both the series, the result surprisingly reveals evidence of anti MNR behavior in addition to MNR behavior [see Fig.…”

“…We have analyzed the data of two types of samples of this material. In the first type of samples (doping series) 53 , boron doping was increased while H 2 dilution was kept constant at 20. The second series (dilution series) 54 consists of samples deposited under constant boron doping (B 2 H 6 /SiH 4 = 1000ppm) and varying H 2 dilution (H 2 /SiH 4 = 15-30).…”