Thermoelectric Properties of PbSe Nanocomposites from Solution-Processed Building Blocks

Abstract

High thermoelectric performance and low material cost are essential to the commercialization of thermoelectric modules. Microstructural design, size effects, and rational band engineering are among the keys to high thermoelectric performance, especially for nanocomposites. Here, we demonstrate a facile and versatile bottom-up approach to produce nanocomposites by heat consolidating solution-processed PbSe nanoparticles with a proper amount of Ag. In this PbSe-Ag system, a certain amount of Ag diffuses into the PbSe matrix and partially substituted Pb while other forms Ag2Se at the interphases. This increased the electrical conductivity and inversed the n-type behavior of PbSe to p-type, which is observed from the positive Seebeck coefficient for PbSe-Ag nanocomposites over the temperature range. Nonetheless, the decrease of total lattice thermal conductivity at high temperature is ascribed to the effective phonon at grain boundaries, Ag2Se nanodomain, and point defect. Overall, we obtained an optimized figure of merit, ZT = 0.97 at 723 K for 5 wt % Ag, a significant improvement of 8.8 times than the pure PbSe. Thus, this partially substituting host atom and the presence of a secondary phase provide another potential strategy to enhance the thermoelectric performance of PbSe, promoting its commercialization.

Inducing High Power Factor in Cu2GeSe3-Based Bulk Materials via (Bi, Zn)-Co-doping

“…As seen in Figure b, the clear peaks of Cu 2p exhibited two peaks at 952.5 and 932.7 eV, originating from Cu 2p 1/2 and Cu 2p 3/2 of Cu + , respectively. , The spectrum of the Ge 2p exhibited two peaks at 1220.6 and 1218.8 eV in Figure c, which were indexed to 2p 3/2 of Ge 4+ in the sample . The two peaks at 55.3 and 54.0 eV in the Se 3d spectrum as seen in Figure d were attributed to Se 3d 3/2 , which was related to the Se 2– . , As illustrated in Figure e, we found that the high-resolution Bi 4f spectrum displayed two peaks at 166.2 and 160.8 eV, which were assigned to Bi 4f 5/2 and Bi 4f 7/2 of Bi 3+ , respectively . While two distinct peaks situated at 163.4 and 158.2 eV were identified as Bi 4f 5/2 and Bi 4f 7/2 of Bi 3+ , severally, exhibiting the presence of Bi 3+ in the sample.…”

“…25 The two peaks at 55.3 and 54.0 eV in the Se 3d spectrum as seen in Figure 4d were attributed to Se 3d 3/2 , which was related to the Se 2− . 24,26 As illustrated in Figure 4e, we found that the high-resolution Bi 4f spectrum displayed two peaks at 166.2 and 160.8 eV, which were assigned to Bi 4f 5/2 and Bi 4f 7/2 of Bi 3+ , respectively. 27 While two distinct peaks situated at 163.4 and 158.2 eV were identified as Bi 4f 5/2 and Bi 4f 7/2 of Bi 3+ , 27 severally, exhibiting the presence of Bi 3+ in the sample.…”

Advances in conducting polymer-based thermoelectric materials and devices

“…As illustrated in Figure 12, we further summarize the future outlooks in the field of conducting polymerbased TE materials and devices [219][220][221][222][223] .…”

Preparation of Heavily Doped P-Type PbSe with High Thermoelectric Performance by the NaCl Salt-Assisted Approach

“…To tune the band structure of p -type PbSe, many different dopants have been examined, such as by substituting Cu/Sr/Ba/K/Ag for Pb or Te/Cl for Se [ 16 , 17 , 18 , 19 ]. In addition, the doping method has also been explored [ 20 , 21 ]. Compared with other processes, the flux method is widely considered to obtain highly crystallized and phase-pure samples [ 22 ].…”