Piezoelectric effects on carrier capturing time in a hybrid p–n junction system: a numerical study using finite element method

The piezoelectric influence on carrier (electrons and holes) trapping time in a hybrid p–n junction system is investigated in this paper. The hybrid nature of the junction is the conceptual combination of p–n junction solar cell and piezoelectricity. The mechanism is that the piezoelectric field induced on the p–n interface can affect the transport of free carriers such as electrons and holes present inside the junction system. These free carriers included are dissociated from excitons which are generated by the light or by the piezoelectric field on the interface via Langevin recombination. The numerical analysis focuses on carrier density (n, p), carrier velocity \((v_{n},v_{p})\), carrier capture cross section \((\sigma _{n},\sigma _{p})\), and carrier capturing time \((\tau _{n},\tau _{p})\) using the finite element method. These parameters are affected by the piezoelectric potential induced by different vertical stresses \((T_{z})\) on the p–n interface. Based on these features, the simulation of the distribution of the carrier (electrons or holes) capturing time over the junction system can be used to analyze the piezophototronic devices where traps are present.