We report the first observation of the vibrational Raman spectrum of hydrogen molecules ${\mathrm{H}}_2$ in crystalline silicon treated with hydrogen atoms at 400 °C. The Raman spectrum of ${\mathrm{H}}_2$ in silicon observed at room temperature exhibits a frequency shift of around $4158{\mathrm{cm}}^{-1\mathrm{}}$ and a very broad half-width of approximately $34{\mathrm{cm}}^{-1\mathrm{}}$. An isotope shift was also detected at around $2990{\mathrm{cm}}^{-1\mathrm{}}$ in silicon treated with deuterium atoms at 400 °C. The frequency shifts of the observed lines are in close agreement with those reported for ${\mathrm{H}}_2$ and ${\mathrm{D}}_2$ in the gas, liquid, and solid phases.

• Received 4 March 1996

DOI:https://doi.org/10.1103/PhysRevLett.77.3161