Interfacial effects in an inorganic/organic composite based on Bi₂Te₃inducing decoupled transport properties and enhanced thermoelectric performance

Abstract

An inorganic/organic composite is suggested for low-temperature thermoelectric applications. An abundant and inexpensive conducting polymer, Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), is introduced to n-type Bi2Te3, thus affording a bulk-phase composite, in which interfacial...

Selective Charge Carrier Transport and Bipolar Conduction in an Inorganic/Organic Bulk-Phase Composite: Optimization for Low-Temperature Thermoelectric Performance

“…This composite exhibits a ZT max value of up to 1.26 at 380 K and an average ZT value ( ZT ave ) of up to 1.23 in the temperature range of 323–423 K (Figures b and S7, Table ), which are nearly twice those of pristine Bi 2 Te 3 . The competitive thermoelectric performance is achieved in the low-temperature region, surpassing that of the Bi 2 Te 3 /PEDOT:PSS composite with 3 wt % PEDOT:PSS, as similarly reported in our previous work. , …”

“…Here, k B represents the Boltzmann constant, e is the electric charge, h indicates the Planck constant, and n stands for the carrier concentration. The effective mass can be used to explain In previous work, we investigated the energy bands via experimental measurements, 24 providing the energy band junction between the two components (Figure 5a)�the work functions (Φ) of the components were derived using the formula Φ = hν − E sec , where hν is the He I energy source and E sec is the secondary electron cutoff energy in ultraviolet photoelectron spectroscopy (UPS) (Figure S6). The work function of Bi 2 Te 3 was verified to be 5.04 eV, which falls within the typical range of Bi 2 Te 3 work functions.…”

Electrochemical assembly of flexible PPy/Bi–Te alloy/PPy thermoelectric composite films with a sandwich-type structure

“…Beyond that, to comprehensively compare the TE performance and the mechanical flexibility of the optimal composite film presented in this study with those of some representative Bi 2 Te 3 /conducting polymer composite films, several important TE parameters are listed in Table S1 (ESI †), from which it can be seen that although the PPy/Bi-Te alloy/PPy composite film exhibits a rather moderate TE performance compared with several excellent n-type Bi 2 Te 3 -based composite films, 31,39,40 it is still one of the best p-type Bi 2 Te 3 /conducting polymer composite films. Regrettably, however, the mechanical flexibility of the Bi 2 Te 3 -based composite films was hardly mentioned in previous studies with only one exception, 39 which is probably ascribed to the relatively poor flexibility of the Bi 2 Te 3 -based composite films, that makes it difficult to accurately measure the retention rate of the TE parameters with bending times.…”

Large-area 2D bismuth antimonide with enhanced thermoelectric properties via multiscale electron–phonon decoupling

“…However, it inevitably deteriorates the electron transportation, but doping or alloying might resolve the problem. When the electrical conductivity is drastically increased owing to extra carrier injection or Fermi level tuning, the thermal conductivity can be decreased simultaneously or increased negligibly, as has been widely investigated in several thermoelectric materials, such as Bi 2 Te 3 , 13,14 Bi 2 Se 3 15 and Bi 0.5 Sb 1.5 Te 3 . 16 For instance, when doping Cu in Bi 2 Se 3 , 15 the electrical conductivity increased by around twofold while the thermal conductivity only changed by 10%.…”