Pressure dependence of phonons and excitons in InSe films prepared by metal-organic chemical vapor deposition

The pressure dependence of the Raman spectra of phase-pure InSe thin films prepared by the low-pressure metal-organic chemical vapor deposition technique has been studied using a diamond-anvil high-pressure cell. Enhancement in the intensities of the Raman modes has been observed as a result of pressure-induced "tuning" of the energy of the M-1-type hyperbolic exciton in InSe at similar to2.54 eV through discrete incident laser photon energies. The pressure coefficients of the phonon modes and of the hyperbolic exciton in InSe have been determined.