Temperature dependency of excitonic effective mass and charge carrier conduction mechanism in CH₃NH₃PbI_3-xCl_x thin films.

ABSTRACT: In this paper we explain the temperature dependence of excitonic effective mass and charge carrier conduction mechanism occurs in CH₃NH₃PbI_3-xCl_x thin films prepared by chemical dip coating (CDC), spray pyrolysis (Spray) and repeated dipping-withdrawing (Dipping). Hall Effect study confirmed that prepared CH₃NH₃PbI_3-xCl_x samples are p-type semiconductor having carrier concentration of the order of ~ 10¹⁶ cm^-3. The charge carrier mobility, mean free path and mean free life time were found to decrease with increasing temperature due to polaronic effect. The excitonic effective mass is estimated to (0.090-0.196)m_e and excitonic binding energy (15-33) meV, well consistent with Wannier-Mott hydrogenic model and the nature of exciton is likely to be Mott-Wannier type. From electrical measurement, it was observed that charge carrier conduction in CH₃NH₃PbI_3-xCl_x is governed by migration of [Formula: see text] and CH₃N [Formula: see text] vacancies and vacancy-assisted diffusion processes depending on temperature.

SUBMITTER: Karim AMMT 

PROVIDER: S-EPMC8144584 | biostudies-literature | 2021 May

REPOSITORIES: biostudies-literature