4 nm; it then began to decrease due to the dominance of density reduction in the evolution
process. Overall, the size and density evolution of the self-assembled Au droplets showed a somewhat similar trend, and the size and density were also quite similar to those on GaAs (111)A. The FFT patterns shown in Figure 7(e-1) to (l-1) also show quite similar behaviors: round bright patterns with higher densities with thinner thicknesses, GS-9973 in vitro such as in Figure 7(e-1) to (h-1), and smaller patterns with reduced density with increased thicknesses, as shown in Figure 7(i-1) to (l-1). Figure 8 shows the EDS graphs with 2 and 20 nm thicknesses on GaAs (100), and the insets of Figure 8c,d,e,f show the SEM images of the samples with 4, 6, 9, and 12 nm thicknesses. Figure 8g summarizes the evolution of Au Mα1 peak at 2.123 KeV along with the increased thicknesses. The Au Mα1 peak at 2.123 KeV and Au Lα1 peak at 9.711 KeV were not observed in the large graph in Figure 8a, while the two Au peaks were clearly observed with the 20-nm thickness in Figure 8b. This could be due to the AZD6738 minimal interaction volume of the 2-nm-thickness sample. The SEM insets clearly
show the size increase along with the decreased AD as a function of increased thickness, and Figure 8g clearly demonstrates the evolution of the Au Mα1 peak at 2.123 KeV as a function of increased thickness. In this work, the self-assembled Au droplets on GaAs (100) again showed quite similar evolution trends compared to those on GaAs (111)A. Based on the previous work [43], when the annealing temperature was varied between 250°C and 550°C on GaAs (100) and (111)A, respectively, the Au droplets showed a clear distinction in terms of their size and density. Indeed, at a lower temperature range between 250°C and 350°C, droplets began to nucleate and develop into wiggly Au nanostructures. Finally, between 400°C and 550°C, dome-shaped Au droplets were fabricated, and during the evolution, GaAs (111)A persistently showed larger-size Au droplets than GaAs (100). Meanwhile, GaAs (111)A cAMP constantly showed
a lower density compared to the GaAs (100). Increased dimension of Au droplets was obvious with the increased annealing temperature based on the thermodynamics and diffusion perspective, as the D S is a direct function of the surface temperature as previously discussed. With different surface indexes under an selleckchem identical growth environment, the L D can be affected by the root mean squared surface roughness (R q); this is caused by several factors such as the atomic step density, surface reconstruction, and dangling bond density [44–46]. The measured R q values were 0.289 nm for GaAs (111)A and 0.322 nm for GaAs (100). Although GaAs (100) possesses a higher value of R q, the size and density between GaAs (111)A and (100) were quite similar within the error range.