Flexible thermopower generation over broad temperature range by PANI/nanorod hybrid-based p–n couples

Abstract

Conducting polymer-based flexible thermoelectric films are an attractive prospect in the field of low-grade heat energy conversion. However, the varieties of n-type polymers are much fewer than the p-type ones, which presents a major obstacle for developing high performance thermoelectric generators. Herein, we demonstrate an n-type polyaniline-based hybrid with Bi₂S₃ nanorods as fillers, showing a Seebeck coefficient of −42 μV K⁻¹ at room temperature, which was realized by precisely controlling the major carrier concentration. Compact and flexible power generator based on solution-processed n-type PANI/Bi₂S₃ and p-type PANI/Te nanorod hybrid films with 7 couples of p–n legs was assembled. The output performance of the device was characterized over a wide temperature range (from room temperature to 473 K). An equivalent thermopower of 224.4 μV per K per couple was achieved at a temperature difference of 90 K. The device also showed good air stability over a one month period. This study provides an approach for integrating PANI-based p-type and n-type thermoelectric films towards efficient power generation utilizing ambient energy for wearable applications.