Do electromagnetic waves outside the visible spectrum have any role in photosynthesis?
Photosynthesis is nearly all visible light. There's usually not enough UV and thermodynamics more or less rules out infrared. Chris covered that pretty spectacularly, but that nearly is significant.

There is some evidence that certain kinds of fungi can use gamma rays or other ionizing radiation for energy, but they're not particularly common. Melanin is used instead of chlorophyll, but apparently 'tooling up' for radiosynthesis(is that a word?) is fairly hard on the cell. It was assumed the melanin was a protective pigment(like it is in humans) and produced only when necessary(also like humans), but these particular ones were discovered growing in the Chernobyl reactor and apparently evolved to continuously produce melanin and absorb ionizing radiation for food. They don't stop producing melanin even on the verge of starvation. Other melanized fungi live in high-radiation environments, like mountaintops and the poles, where there is more UV and cosmic rays and things. 

Fun fact aside: Fossilized melanized fungal spores turn up at the K-T boundary when the earth had no magnetic field and therefore higher radiation flux at the surface (see paper linked above and Hulot &amp; Gallet, 2003 for more).