Elevated thermoelectric figure of merit of n-type amorphous silicon by efficient electrical doping process
Artikel i vetenskaplig tidskrift, 2018

The currently dominant thermoelectric (TE) materials used in low to medium temperature range contain Tellurium that is rare and mild-toxic. Silicon is earth abundant and environment friendly, but it is characterized by a poor TE efficiency with a low figure of merit, ZT. In this work, we report that ZT of amorphous silicon (a-Si) thin films can be enhanced by 7 orders of magnitude, reaching ∼0.64 ± 0.13 at room temperature, by means of arsenic ion implantation followed by low-temperature dopant activation. The dopant introduction employed represents a highly controllable doping technique used in standard silicon technology. It is found that the significant enhancement of ZT achieved is primarily due to a significant improvement of electrical conductivity by doping without crystallization so as to maintain the thermal conductivity and Seebeck coefficient at the level determined by the amorphous state of the silicon films. Our results open up a new route towards enabling a-Si as a prominent TE material for cost-efficient and environment-friendly TE applications at room temperature.

Energy harvesting

Thermoelectrics

Electrical conductivity

Electrical doping

Amorphous silicon

Författare

Debashree Banerjee

Uppsala universitet

Central Electronics Engineering Research Institute

Örjan Vallin

Uppsala universitet

Majid Kabiri Samani

Chalmers, Mikroteknologi och nanovetenskap (MC2), Elektronikmaterial och system

Subimal Majee

Uppsala universitet

Shi Li Zhang

Uppsala universitet

Johan Liu

Shanghai University

Chalmers, Mikroteknologi och nanovetenskap (MC2), Elektronikmaterial och system

Zhi Bin Zhang

Uppsala universitet

Nano Energy

2211-2855 (ISSN)

Vol. 44 89-94

Ämneskategorier

Keramteknik

Materialkemi

Annan materialteknik

DOI

10.1016/j.nanoen.2017.11.060