Solvothermal preparation and characterization of sheet-like CuInSe2 with hierarchically mesoporous structures

By using a solvothermal reaction in mixed solvent of ethylenediamine and ethylene glycol, nanoparticle-assembled sheet-like CuInSe2 with hierarchically mesoporous structures were successfully fabricated with the absence of any template or structure-directing agent. The as-synthesized products were characterized by XRD, EDX, FESEM, TEM, HRTEM, BET nitrogen adsorption and NIR absorption spectrum. The possible formation mechanism was simply discussed. The size of mesopores is hierarchically distributed in the range of 2–30 nm and the specific surface area was estimated to be 10.15 m2/g. The value of band gap (Eg) was calculated to be 1.00 eV based on its NIR absorption spectrum.