These devices would be difficult to built, and just about impossible to have a long lifetime. Remember how UV sterilization works? It breaks the chemical bonds of organic compounds. All organic compound bonds are covalent bonds. That means the UV photon has to be of higher energy than the bond energy in the organic compounds being disrupted. The bad news is that silicon chemical bonds have very similar bond energies to carbon bond energies, so it would be very difficult to construct such an LED from any silicon based material. A 265nm photon is about 4.8 ev, and that is actually higher than the bond energy of all covalent chemical bonds. Consequently an LED with a 265nm output will tend towards self destruction. Mercury vapor devices put most of their energy into photons that are slightly higher than 4.8 ev. The electric excitation of mercury atoms can elevate their energy states so that when they drop back to ground state, they put the energy they give up into a 4.9 ev photon. Since there are no mercury bonds involved, this isn’t a problem, but ultimately it actually does damage the SiO2 bonds (glass), and that is one of the reasons Mercury Vapor UV sources don’t have an especially long life. The compounds that result from the disruption of the chemical bonds in the glass are not particularly transparent to photons of this energy.