Improved thermoelectric properties of n-type polycrystalline SnSe via carrier concentration optimization

Thermoelectric properties of Pnma and R3m GeS and GeSe

“…(This may be compared with the p-type ZT max of 1.56 and 2.29 along the c directions, which are both ∼10% larger than the average values of 1.39 and 2.07.) Given that successful n-type doping of both SnS and SnSe has been demonstrated, and at comparable n to what we predict is needed, 93 this is also a potentially significant finding.…”

“…Studies on n-doped SnS for PV applications have demonstrated n ≈ 10 18 in halogen-doped single crystals and n ≈ 5 × 10 18 cm −3 in Sn 1− x Pb x S thin films, 92 while the recent study in ref. 93 achieved n ≈ 10 19 cm −3 in Sn 0.95 Se with 1% HfCl 4 . We therefore tentatively suggest that the lower n required to achieve the predicted ZT max in the n-doped chalcogenides may be achievable with further optimisation.…”

“…by substituting Sn with Ag or Na, 38,39 or by promoting Sn vacancies. 90,91 However, n-type (electron) doping has also been reported for both SnS and SnSe, 92,93 and has been predicted to lead to favourable properties in Pnma GeS. 45 We therefore considered both types of doping.…”

Enhancing Electrical Transport Performance of Polycrystalline Tin Selenide by Doping Different Elements

“…[92,93] Ge et al prepared Hf and Cl co-doped N-type polycrystalline SnSe 0.95 samples by solid-phase method. [94] Hf proved to be an effective cationic dopant, which could bring a large number of electrons and suppress mass fluctuations in thermal conductivity, and the introduction of Cl further contributed electrons. SnSe 0.95 þ 1 wt% HfCl 4 sample obtained a high electrical conductivity of 33 S cm À1 at 773 K, about five times that of SnSe 0.95 sample.…”

Realizing High Thermoelectric Properties in Bi2S3 Bulk via Band Engineering and Nanorods Compositing

“…[25,26] In addition, Hf exhibits good performance in several thermoelectric materials. [27][28][29][30] Therefore, in this study, hafnium chloride (HfCl 4 ) was used as the n-type dopant to enhance the electrical transport properties of Bi 2 S 3 . The results demonstrate that hafnium chloride doping effectively optimizes the electrical conductivity of Bi 2 S 3 polycrystalline materials, resulting in a significantly enhanced power factor, doped samples doped with 0.75 wt% HfCl 4 exhibited an average power factor of 464 μWm −1 K −2 in the tested temperature range, reaching a ZT peak of 0.47 at 673 K. To further optimize the thermal conductivity, we synthesized Bi 2 S 3 nanorods through hydrothermal methods and combined them with the doped sample in different ratios to obtain a bulk sample through SPS sintering.…”