Abstract
Bismuth-telluride (Bi2Te3) is considered to have the best thermoelectric properties at room temperature(ca.300 K).Thus,synthesis and improvement of Bi2Te3 and its derivatives quickly and cost-effectively at favorite temperatures are of interests.Recently,doping fluorine (F) into electronic materials (e.g.,FTO) has gained attention;however,it is not applied to Bi2Te3 till now.Here,our synthesis of F-doped Bi2Te3 for thermoelectric application is introduced using spark plasma sintering (SPS) for Bi2Te3 preparation and reactive ion etching (RIE,with SF6 gas) for F-doping.The exposure time of SF6 plasma is adjusted to evaluate F-doping effect on the thermoelectric properties of the samples.During characterizations,the increased electrical conductivity and the improved Seebeck coefficient of F-doped Bi2Te3 are observed.Through spectroscopic studies and DFT calculations,the main mechanism behind that improvement is unveiled.It also emphasizes the essential role of the F-doping (optimum treatment time of 40 s) in in-creasing the carrier concentrations as well as electrical conductivity.With increasing measurement tem-perature (300-510 K),F-doping raises the figure of merit of electron rich Bi2Te3 from 1.0 to 1.11 (peaked at 390 K).
NETL
NSTL
维普
万方数据