How can an article talk about more efficient solar cells and not even mention in passing technology already available such as triple junction gallium arsenide?

How can an article talk about more efficient solar cells and not even mention in passing technology already available such as triple junction gallium arsenide? I mean the mars rovers are using 30+% efficient cells NOW. The cost are much higher than silicon, but this is working producible technology that we just need to figure out how to lower costs of.