The quantum confinements of an exciton bound to a single Te (X/Te) and to many Te (X/Te-n) were observed for the first time in ZnSe/Zn1-yCdySe quantum wells with a thin ZnSe1-xTex (very low x < 0.01) layer inserted at the center of a Zn1-yCdySe quantum well. The binding energies of X/Te for the 5.0, 2.5, and 1.4 nm wells were 69, 8 1, and 83 meV, respectively. In the case of ZnSe/ZnSe1-xTex quantum well structures, the quantum confinement of a deep energy level, Te cluster bound exciton, was investigated. Current results imply a tiny wave-function size for the X/Te, X/Te-n, and exciton bound to a Te cluster. (C) 2003 Elsevier Science B.V. All rights reserved.