Enhanced Thermoelectric Performance of the F4-TCNQ Doped Sn-based Perovskite Thin Films

Описание: by Dr. Luyao Zheng, Materials Science and Engineering, Penn State
April 29, 2021

Abstract: In the past decade, great effects have been devoted to the development of organic-inorganic hybrid perovskites for approaching efficient photovoltaics, but fewer attention has been paid on their thermoelectric applications. In this study, for the first time, we report thermoelectric performance of the 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ) doped NH2CHNH2SnI3 (FASnI3) thin films. It is found that the electrical conductivities of the F4-TCNQ doped FASnI3 thin films are increased and then decreased along with increased doping levels of F4-TCNQ. Systematically studies indicate that enhanced electrical conductivities are attributed to the increased charge carrier concentrations and mobilities, and superior film morphologies of the F4-TCNQ doped FASnI3 thin films, and decreased electrical conductivities are originated from the cracks and poor film morphology of the F4-TCNQ doped FASnI3 thin films induced by excess F4-TCNQ dopants. The quantitative thermal conductivity scanning thermal microscopy studies reveal that the F4-TCNQ doped FASnI3 thin films exhibit ultralow thermal conductivities. Moreover, the thermoelectric performance of the F4-TCNQ doped FASnI3 thin films are investigated. It is found that the F4-TCNQ doped FASnI3 thin films exhibit a Seebeck coefficient of ~310 μV K-1, a power factor of ~ 130 μW m-1 K-2 and a ZT value of ~0.19 at room temperature. All these results demonstrate that our studies open a door for exploring cost-effective less-toxic organic-inorganic hybrid perovskites in the application of heat-to-electricity conversion at room temperature.