uv is produced via a chemical reaction in the bulbs. uv is radiation and not light per se. Diodes are not designed to produce that chemical reaction like t5 bulbs. some led manufacturers say they offer uv in there qb but from what I understand, it isn't possible.
The trouble with most light systems and the spectrum they produce is that it is exclusively focused on photosynthesis and not the other parameters which contribute to quality. There are many sources of good looking bud that doesn't really smoke well or taste the best because it is missing these...