Optical Absorption Of Electron Intersubband Transition In Multi-quantum Wells Of ZnO/ZnMgO

Aimed at multi-quantum wells（MQWs）consisting of ZnO/Zn_1-x-x Mg_xO and taking into account of the built-in electric field（BEFs）,this thesis discusses emphatically the influence of inter-well coupling,size and ternary mixed on optical absorption of electron intersubband transition in MQWs.Using the finite difference method,the energy levels of ground,the first excited state,the second excited state and their corresponding wave functions of electrons in conduction band are solved self-consistently the Schr?dinger equation and Poisson equation.Furthermore,the intersubband optical absorption coefficients（IOACs）of wurtzite and zinc-blende structures are calculated by the Fermi-golden rules in the range of 0.1<x<0.9.IOACs are fitted by a weight model proposed by our group in the scope of mixed phases for 0.37<x<0.62.The results are analyzed and discussed.Firstly,the relative research history,current situation and application prospect of electron intersubband optical absorption in semiconductor quantum wells are briefly introduced.The research status and the existed shortcoming of electron intersubband optical absorption in MQWs are mainly explained to induce the contents of this thesis:the modulation of the MQW structures on optical absorption of electron intersubband transition.Furthermore,the effects of the number of quantum wells,well widths,and Mg component on the optical absorption of electron intersubband transition are discussed theoretically in detail.Our calculated results show that:under the influence of BEFs,the number of quantum wells,size and mixed crystal components can effectively modulate IOACs to improve the efficiency of photoelectric absorption in MQWs.The peak positions of IOACs appear red shifts first and then blue shifts with increase of the number of quantum wells,but blue shifts occur with increase of well width and Mg composition.Finally,the fitted results for mixed phase in MQW structures are given and compared with that of experiments.Our results are helpful for infrared photoelectric device designs and related experiments.