Unveiling InTe for flexible thermoelectric applications with enhanced performance via Bi/Se co-doping and MnO₂ integration

TL;DR

This paper introduces InTe as a printable, flexible thermoelectric material with improved performance through co-doping and MnO₂ integration.

Contribution

The first screen-printed flexible thermoelectric generators based on InTe with enhanced performance via Bi/Se co-doping and MnO₂ heterojunctions.

Findings

In0.94Bi0.06Te0.97Se0.03 achieved a Seebeck coefficient of ~1320 µV/K and a power output of ~29.45 nW.

Incorporating MnO₂ increased peak power output to 48.41 nW, a 1.64-fold improvement.

FTEGs showed 2% resistance variation after 500 bending cycles, indicating good mechanical durability.

Abstract

Conventional thermoelectric materials are limited by rigidity, high synthesis costs, and poor compatibility with flexible devices. Despite progress, the development of novel, low-cost, and scalable materials for flexible thermoelectrics remains limited. The novelty of this work lies in introducing InTe as a printable thermoelectric material and demonstrating the first screen-printed flexible thermoelectric generators (FTEGs) based on InTe. Pristine and Bi/Se co-doped InTe were synthesised via solid-state reaction and fabricated through a cost-effective, scalable screen-printing method. Co-doping effectively tuned the crystallinity, carrier concentration, mobility, and band structure. Among the co-doped samples, In0.94Bi0.06Te0.97Se0.03 achieved a Seebeck coefficient of ~ 1320 µV/K and showed a maximum power output of ~ 29.45 nW at a temperature gradient of 100 K. The other novelty of this work is the incorporation of MnO₂ to form a printed p–n heterojunction, which improves the conductive pathway, leading to a peak power output of 48.41 nW, approximately 1.64 times higher than that of the In0.94Bi0.06Te0.97Se0.03 sample. The FTEGs exhibited approximately 2% resistance variation after 500 bending cycles and at various angles, confirming excellent mechanical durability. This work establishes InTe as a promising printable thermoelectric material and highlights co-doping and MnO2 incorporation as powerful strategies for flexible energy harvesting.

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