Nanocrystalline lanthanum boride thin films by femtosecond pulsed laser deposition as efficient emitters in hybrid thermionic-photovoltaic energy converters

•Thin films based on LaB6 were produced for novel hybrid thermionic converters.•Deposition assisted by fs laser was used for the first time for films’ fabrication.•A detailed physical-chemical study on surface and bulky properties was performed.•Experimental conditions were optimized for enhancing the material’s properties.•Optimal work function and emissivity values were achieved for practical applications.