This chapter discusses the excitonic processes related to charge carrier–phonon interaction in quantum wells (QWs). The process of relaxation plays a significant role in the properties of photoexcited semiconductor systems. There are two important processes in the relaxation in QWs, intraband and interband. The chapter first considers intraband transitions of relaxation and then interband transitions. In optical spectroscopic experiments such as transmission spectroscopy, photoluminescence, and four-wave mixing, ideal noninteracting excitons show very sharp optical peaks in their line shapes. The chapter presents a theory to calculate the free exciton homogeneous linewidth and dephasing rate at low excitation densities due to exciton–acoustic phonon interaction as a function of the lattice temperature, exciton temperature, well width, and exciton density in QWs. It explains the localization of free excitons due to interface roughness through the nonradiative processes in QWs as a transition from a free exciton state to a localized exciton state.
|Title of host publication||Optical Properties of Materials and Their Applications|
|Place of Publication||New Jersey|
|Publisher||John Wiley & Sons|
|Number of pages||37|
|Publication status||Published - 2020|