The photochromic and thermochromic properties of molybdenum oxide (MoO3) thin films doped with zinc selenide (ZnSe) were studied. The films were deposited on glass substrates by thermal evaporation of MoO3-ZnSe powder mixtures. The characteristic optical absorption band attributed to color center formation indicated an enhanced photochromic effect for MoO3 films doped with ZnSe 5 mol% relative to undoped MoO3 samples. In addition, the thermochromic effect was most pronounced for ZnSe 5 mol% samples annealed at 23-125 degrees C, and for undoped samples annealed at 125-225 degrees C. The chromogenic properties were essentially suppressed for MoO3 doped with ZnSe 10 mol%. (C) 2009 Elsevier B.V. All rights reserved.