Bi2Te3/Sb2Te3 Heterojunction and Thermophotovoltaic Cells Absorbing the Radiation from Room-temperature Surroundings

TL;DR

This study demonstrates that Bi2Te3/Sb2Te3 heterojunction thermophotovoltaic cells can convert infrared radiation from room-temperature surroundings into electricity, highlighting their potential for energy harvesting in ambient conditions.

Contribution

The paper reports the fabrication and analysis of Bi2Te3/Sb2Te3 thin film thermophotovoltaic cells, revealing unique diffusion behavior and their ability to generate power from room-temperature infrared radiation.

Findings

Bi2Te3/Sb2Te3 heterojunctions form via same-direction diffusion of carriers.

Heterojunctions exhibit linear I-V characteristics due to intrinsic carriers.

Cells can produce electrical power under ambient infrared radiation.

Abstract

The thermophotovoltaic cells which can convert the infrared radiation from room-temperature surroundings into electricity are of significance due to their potential applications in many fields. In this work, narrow bandgap Bi2Te3/Sb2Te3 thin film thermophotovoltaic cells were fabricated, and the formation mechanism of Bi2Te3/Sb2Te3 p-n heterojunctions was investigated. During the formation of the heterojunctions at room temperature, both electrons and holes diffuse in the same direction from n-type Bi2Te3 thin films to p-type Sb2Te3 thin films rather than conventional bi-directional diffusion. Because the strong intrinsic excitation generates a large number of intrinsic carriers which weaken the built-in electric field of the heterojunctions, their I-V curves become similar to straight lines. It is also demonstrated that Bi2Te3/Sb2Te3 thermophotovoltaic cells can output electrical power under the infrared radiation from a room-temperature heat source. This work proves that it is possible to convert the infrared radiation from dark and room-temperature surroundings into electricity through narrow bandgap thermophotovoltaic cells.