“…A shoulder lies between the InAs-like LO mode and the InSb-like LO mode for all the samples. This shoulder has been observed by Li [15] and Cherng [16] for InAsSb, by Kakimoto [17] for InGaAs, and was interpreted as being due to disorder-activated optical (DAO) phonons. For sample A4, a broadband with Raman shift 136 cm −1 is observed.…”