Anharmonic phonon coupling and decay of optical phonons in polycrystalline CdSe thin films. Issue 16 (15th August 2022)

• Record Type: Journal Article
• Authors: Iqbal, Muhammad Faisal; Ullah, Kaleem; Yaqoob, Manzar Mushaf; Khan, Abbas Ahmad; Farid, Sumbal; Zhu, Peng; Wang, Deliang
• Is Part Of: Ceramics international. Volume 48:Issue 16(2022)
• Page Start: 23862
• Page End: 23869
• Publication Date: 2022-08-15
• Subjects: Anharmonic phonon coupling -- FDTD simulations -- Surface-enhanced Raman scattering -- Thin films -- CdSe; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.04.351
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: The lifetime of longitudinal optical (LO) phonon is a key parameter that significantly affects the performance of semiconductor optoelectronic devices. Herein, in situ temperature-dependent resonance Raman scattering experiment has been performed to study the phonon anharmonicity in sputter-deposited CdSe thin films. Strong multiphonon scattering processes involving 1LO + TO, 2LO-TO, 2LO + TO, 2LO+ E 2 low and TO- E 2 low are well resolved and allow us to investigate the anharmonic decay of 1LO, 2LO, and 1LO + TO phonon modes. Fundamental 1LO and its overtone 2LO phonon modes asymmetrically decay into a pair of transverse optical (TO) and transverse acoustical (TA) phonon at the 'A' point of the Brillouin zone along Γ−A direction. With increasing temperature, enhanced anharmonic phonon coupling and phonon decay led to an almost linear decrease in the wavenumber of both modes and a nearly linear increase in their full-width half maxima. The composite 1LO + TO mode exhibited a ∼ 30% faster decay rate compared to the decay rate of the fundamental 1LO phonon mode.