Formation and Transient Photovoltaic Properties of ZnO/Si …
311
Fig. 6 In-depth elemental distributions in SIMS profiling analysis of a 67-nm thick ZnO film
deposited onto the Si substrate
interface at the beginning of the deposition of AZO. As reported by Bikowski et al.
[48], the condensation and re-evaporation effects can be related to the vapor pressure
during the growth. Moreover, according to Alcock et al. [49], the evaporation rate
of Zn is much greater than that of Al. In contrast, metal oxides tend to reside on
the surface much stronger than pure metals since the pressure of vapor is considerably smaller in the former case. Furthermore, the formation of aluminum oxide
or aluminum-doped zinc oxide is energetically favorable compared to formation of
zinc oxide. Therefore, this can explain the domination of the segregated aluminum
mentioned above during the deposition at high substrate temperatures.
311
Fig. 6 In-depth elemental distributions in SIMS profiling analysis of a 67-nm thick ZnO film
deposited onto the Si substrate
interface at the beginning of the deposition of AZO. As reported by Bikowski et al.
[48], the condensation and re-evaporation effects can be related to the vapor pressure
during the growth. Moreover, according to Alcock et al. [49], the evaporation rate
of Zn is much greater than that of Al. In contrast, metal oxides tend to reside on
the surface much stronger than pure metals since the pressure of vapor is considerably smaller in the former case. Furthermore, the formation of aluminum oxide
or aluminum-doped zinc oxide is energetically favorable compared to formation of
zinc oxide. Therefore, this can explain the domination of the segregated aluminum
mentioned above during the deposition at high substrate temperatures.