Light Absorption And Refractive Index Changes Of Electron Interband Transition In Wurtzite ZnO/Zn_1-xMg_xO Asymmetric Double Quantum Wells

Considering the effects of the built-in electric field?BEF?and bend factor in wurtzite ZnO/Zn_1-xMg_xO asymmetric double quantum wells?ADQWs?,using the finite difference method to solve self-consistently the Schr?dinger equation and Poisson equation,the energy levels and corresponding wave functions of electrons?holes?are obtained.Furthermore,using Fermi's golden rule,the linear and nonlinear optical absorption coefficients?OACs?and refractive index changes?RICs?of electron interband transitions are derived.And the influences of ternary mixed crystal?TMC?,size and incident light intensity on the OACs and RICs are discussed.Firstly,the research history and development state of the relative problems of quantum wells are briefly introduced,and the research progress of OACs and RICs of electron interband transitions in ZnO/MgZnO quantum wells is described in detail.Aiming at the existing problems,the theory and model of this thesis are given.The numerical solution by calculation is obtained and discussed.The results show that strong BEF can reach MV/cm in ZnO/Zn_1-xMg_xO ADQWs and the system is sensitive to the TMC and size effects.When the width of left well is smaller and the thickness of center barrier is larger,the coupling effects of double wells and the wave functions of electron and hole are strengthened.It is also found that the spatial separation of electron and the hole wave functions decrease and distribute in the same well;The barrier height and BEF are enhanced with increase of Mg component when the size is fixed,and the energy levels difference of electrons and holes become larger,and the peaks of OACs and RICs present a blue shift and the peaks decrease;With the increase of center barrier width,the corresponding peaks decrease and present a red shift;With increasing the thickness of right well,the corresponding peaks firstly increase then decrease and present a red shift.In addition,the incident optical intensity?IOI?can modulate OACs and RICs,and the peaks of OACs and RICs decrease as the increase of IOI.The results obtained in this paper can provide theoretical guidance for related experiments.