Higher Suitability of NbMoTaW over Its Elemental Metals for Laser Induced Periodic Surface Structure/Particle-Aggregate UV-to-MIR Ultrabroadband Absorber

The peculiarity and higher suitability of NbMoTaW over its composed elemental metals for femtosecond laser induced LIPSS/particle-aggregate UV-to-MIR ultrabroadband absorber are firstly revealed. The performance of ultrabroadband absorbers is adjustable by changing the density of NbMoTaW particle aggregates on laser induced periodic surface structures (LIPSS) with increasing repetition rate from 0.5 to 1 MHz and laser power from 1 to 12 W till a whole coverage at 12 W and 1 MHz, under which condition only lower-performance microstripes consisting of particle-aggregate and LIPSS (on Mo, Ta, and W) or macropore/LIPSS micro/nanostructures (on Nb) are achievable on elemental metals. NbMoTaW-LIPSS decorated by a few particle aggregates is more suitable than LIPSS itself to be used as selective solar absorber, indicating the capacity of deposited particle aggregates to modulate absorbance selectivity. It is deduced that NbMoTaW-RHEA should possess a lower melting temperature than W and a high electron-phonon coupling constant, facilitating nano-structuring/nano-synthesis.