Electro-mechanical-carrier coupling model of single piezoelectric semiconductor fiber pull-out

Recently, piezoelectric semiconductor (PS) fiber composite materials are widely used in flexible and wearable optoelectronics owing to their unique properties of possessing piezoelectricity and semiconduction simultaneously. It is of great importance to investigate the interfacial characteristics of PS fiber composites in case of interfacial damages between PS fiber and elastic matrix. In this paper, a theoretical model of single piezoelectric semiconductor fiber pull-out is established to study the electro-mechanical-carrier coupling characteristics and interfacial behaviors of fiber/matrix system. Based on the shear-lag theory, the stress transfer relationship between PS fiber and elastic matrix is investigated. Closed form solutions of distributions of relevant electromechanical fields and carrier perturbation are obtained as well. The results show that the change of material parameters and structure parameters can effectively tune the mechanical, electrical and interfacial properties of composite system. In addition, the value of initial carrier concentration which reveals the semiconducting property of PS fiber has a significant influence on the distributions of electromechanical fields. The findings are valuable for adjusting the electromechanical coupling behaviors of PS fiber via specific structure design and material combination in practical applications of piezotronics.