Most common name for this kind of image, where the sun illuminates the horizon

Besides the space horizon and space sunrise google image searches mentioned previously, diamond ring eclipse and Baily's beads may be useful to look for. (Granted, if you want some illuminated planet surface to be visible, space sunrise seems to be the proper thing to look for.)

As noted in dictionary.reference.com, diamond ring effect refers to

a phenomenon, sometimes observed immediately before and after a total eclipse of the sun, in which one of Baily's beads is much brighter than the others, resembling a diamond ring around the moon.

The Baily's beads article in wikipedia explains the diamond ring effect at more length, and also notes:

The name is in honor of Francis Baily who first provided an exact explanation of the phenomenon in 1836. The diamond ring effect is seen when only one bead is left; a shining diamond set in a bright ring around the lunar silhouette.