Powder Bi2Se3 was produced through Mechanical Alloying (MA) and Melting Technique (MT) routes. Structural, optical and photoacoustic properties were evaluated by X-ray diffraction (XRD), Raman Spectroscopy (RS) and Photoacoustic Absorption Spectroscopy (PAS). Minority Bi2O2Se phase was nucleated in both samples. PAS measurements showed a thermal diffusivity reduction of 40% for Bi2Se3 produced through MA when compared with Bi2Se3 produced by MT. In addition, thermal diffusivity of Bi2Se3 obtained by MA and MT was a new report in literature.