ThepresentworkreportedtheinfluenceofGecontentvariationontheopticalpropertiesof
GexSe50Te50-x (x¼0, 5,15,20,35at%).Vacuumthermalevaporationtechniquewas
employedtoprepareamorphousGexSe50Te50x thinfilms.Thestoichiometryofthe
chemicalcompositionwascheckedbyenergydispersiveX-rayspectroscopy(EDX),whereas
thethinfilmsstructurewasdeterminedbyanX-raydiffractionandascanningelectron
microscope(SEM).Theopticalabsorptionmeasurementswereperformedatroom
temperatureinthewavelengthrangeof200–900nm.Manyopticalconstantswere
calculatedforthestudiedthinfilmsutilizingtheopticalabsorptiondata.Itwasobserved
thattheopticalabsorptionmechanismfollowstheruleofthealloweddirecttransition.The
opticalbandgapwasfoundtoincreasefrom2.31to2.60eVastheGecontentincreases
from0to35at%.Thisresultwasexplainedintermsofthechemicalbondapproach.