Quantum size effects in simple colored glass

Finite size effects have been observed at low temperatures for electrons confined to semiconductor microcrystallites embedded in a simple borosilicate glass. Luminescence data reveal large electronic energy shifts relative to bulk energy levels which can be used to calculate the confinement energy of the localized electrons. This system provides an attractive alternative to quantum well heterostructures, permitting direct optical studies of electron-confinement effects over a wide range of temperatures. © 1985 The American Physical Society.