Effect of gas pressure on current-voltage characteristics of amorphous carbon film/silicon heterojunction

Abstract

Resonant structures based on amorphous silicon suboxide doped with Er 3 + with silicon nanoclusters for an efficient emission at 1550 nm

Electrical transport properties of amorphous CNx/p‐Si heterostructures

“…2a, it is clear that in the voltage‐dependent current density J plots in the reverse voltage range measured at different temperatures that log J approaches a saturation state, as that reported by Hastas et al 9 even though in the present measurement range log J is not saturated. The current density J in the present heterostructure is almost in the same order of magnitude with those reported on the similar devices by other authors 9, 10–13. For analyzing the characteristic of the I – V curves in the low‐voltage range, Fig.…”

“…Therefore, the slope of the log I –log V curves at small voltages is larger than 1. The linear log I –log V relations were also observed in the amorphous C and CN x /n‐Si heterostructures 10–14 and amorphous C/p‐Si structures 9. Meanwhile, in the bottom‐right inset of Fig.…”

“…The log I –log V curves are not a straight line as temperature decreases from 120 to 90 K, suggesting that the electrical transport mechanism is different from that above 120 K. The slope of the log I –log V curves in the top‐right inset of Fig. 3b changes from 3.41 for the lower forward voltages to 4.89 at 305 K, and 5.03 to 13.15 at 130 K for the higher forward voltages, indicating the transition of the dominating current mechanisms from Ohmic to space charge limited current or tunneling emission mechanism as temperature decreases, which can be ascribed to the facts that the interface accommodates more degenerate defect energy levels from the defects and traps, presenting diffusions to limit the current 10–12. However, the Ohmic regime with the slope of 1 is never obtained, even for a small applied bias of 0.2 V, which can be explained by the facts that there are natural oxide SiO 2 layer between amorphous CN x and p‐Si substrates, and the electrons must tunnel through this layer at a small voltage.…”

Ethanol gas sensitivity of carbon nanotip arrays/n-Si heterojunctions at room temperature

“…Moreover, nanotip arrays become thicker when the deposition time is prolonged from 10 to 15 min. As we noted, we cannot produce such carbon nanotips under lower argon pressures, such as 0.5, 2.0, and 4.0 Pa. 17 The results show that the argon pressure plays an important role on producing carbon nanotips.…”

“…The Raman results were consistent with the results reported before. 17 From the spectra, three main variations are observed: ͑1͒ one obvious G peak around 1550 cm −1 for all four films illustrates the diamondlike carbon characteristics of the carbon films deposited by direct current magnetron sputtering, ͑2͒ the G band shifts to higher wave numbers with increasing deposition pressure, and ͑3͒ the I D / I G ratio of the carbon film deposited at 10 Pa is larger than that of the other carbon films. All these phenomena suggest that the film deposited at 10 Pa has the strongest sp 2 bonding.…”