what experimental support is available for de-broglie's concept?

The experiment performed by Davisson and Germer supports the de-Broglie's concept. It was observed that wavelength of the electron wave as determined from diffraction experiment was in agreement with the wavelength calculated by applying de-Broglie'e equation.

A bit about Davisson and Germer experiment.

Davisson and Germer designed and built a vacuum apparatus for the purpose of measuring the energies of electrons scattered from a metal surface. Electrons from a heated filament were accelerated by a voltage and allowed to strike the surface of nickel metal.

The electron beam was directed at the nickel target, which could be rotated to observe angular dependence of the scattered electrons. Their electron detector (called a Faraday box) was mounted on an arc so that it could be rotated to observe electrons at different angles. It was a great surprise to them to find that at certain angles there was a peak in the intensity of the scattered electron beam. This peak indicated wave behavior for the electrons, and could be interpreted by the Bragg law to give values for the lattice spacing in the nickel crystal.

The experimental data above, reproduced above Davisson's article, shows repeated peaks of scattered electron intensity with increasing accelerating voltage. This data was collected at a fixed scattering angle. Using the Bragg law, the deBroglie wavelength expression, and the kinetic energy of the accelerated electrons gives the relationship:-

1/λ = n / 2 d sinΘ = p /h = √2mE/h

You observe relationship between electron wavelength, Bragg law, deBroglie equation.