Abstract
In the evolution of pervasive electronics, it is imperative to significantly reduce the energy consumption of power systems and embrace sustainable materials and fabrication processes with minimal carbon footprint. Within this context, thermoelectric generators (TEGs) have garnered substantial attention in recent years because of the readily available thermal gradients in the environment, making them a promising energy-harvesting technology. Current commercial room-temperature thermoelectrics are based on scarce, expensive, and/or toxic V-VI chalcogenide materials, which limit their widespread use. Thermoelectric polymers partially address this issue, and as such, they have been intensively studied in the field in the past decade. However, less popular materials have recently appeared to respond to the challenges of room-temperature thermoelectrics in terms of sustainability and cost. In this contribution, we comprehensively review the latest advancements in emerging alternative materials with the potential to pave the way for the next generation of sustainable TEGs. This upcoming generation includes flexible and printed TEGs for applications like wearables or the Internet of Things.