While they don't necessarily require plants, in 99% of cases, your shrimp would appreciate it, and they'd definitely thrive in tanks with plants. Freshwater shrimp do incredibly well in planted tanks, and there are numerous varieties to choose from.  There's quite a selection to choose from, to mention Anubias Congensis, Moss Balls, Rotalas, Duckweed, Java Moss/Fern, Cypts, and even carpet plants like Dwarf Baby Tears. Another great choice would be Subwassertang which because of its minimal lighting requirements, it's an ideal floating aquatic plant for any aquarium, and it does especially well with shrimps.