Nontoxic and Abundant Copper Zinc Tin Sulfide Nanocrystals for Potential High-Temperature Thermoelectric Energy Harvesting

Abstract

Improving energy/fuel efficiency by converting waste heat into electricity using thermoelectric materials is of great interest due to its simplicity and reliability. However, many thermoelectric materials are composed of either toxic or scarce elements. Here, we report the experimental realization of using nontoxic and abundant copper zinc tin sulfide (CZTS) nanocrystals for potential thermoelectric applications. The CZTS nanocrystals can be synthesized in large quantities from solution phase reaction and compressed into robust bulk pellets through spark plasma sintering and hot press while still maintaining nanoscale grain size inside. Electrical and thermal measurements have been performed from 300 to 700 K to understand the electron and phonon transports. Extra copper doping during the nanocrystal synthesis introduces a significant improvement in the performance.

Research Update: Cu–S based synthetic minerals as efficient thermoelectric materials at medium temperatures

“…21 The nanocrystals were compressed into bulk pellets while maintaining the 10 nm grain size. The value of S of the pellet was largely enhanced and that of κ was reduced compared to those of the bulk sample mentioned above, leading to κ = 0.97 W/Km, S = 990 µV/K, and ZT = 0.026 at 700 K. The enhancement in S was expected to be due to quantum confinement of the electronic structure and/or energy filtering that occurred at grain-grain interfaces.…”

Composition Modulation of Ag2Te Nanowires for Tunable Electrical and Thermal Properties

“…To remove the surface ligands, the Ag 2 Te nanowires are dispersed in 800 ml ethanol and mixed with 80 ml N 2 H 4 •H 2 O under vigorous stirring for a day. [1][2][3] The nanowires are then collected with centrifugation and washed with DI water for three times.…”

A First-Principles Theoretical Study on the Thermoelectric Properties of the Compound Cu5AlSn2S8

“…Recently, some researchers have studied the TE properties of Cu 2 SnS 3 , Cu 2 ZnSnS 4 , and Cu 2 SnSe 3 , and the results have shown these materials are promising candidates for TE applications in the middle-temperature range. [43][44][45] Xi et al studied the effects of doping on the TE properties of Cu 2 SnS 3 and Cu 2 SnSe 3 , found the regime where the best performance was realized, and estimated the maximum ZT of Cu 2 SnS 3 and Cu 2 SnSe 3 . 43 Yang et al synthesized Cu 2 ZnSnS 4 nanocrystals and achieved a ZT value of 0.14 at 700 K. 44 Fan et al studied the thermoelectric properties of Cu 3Àx Sn x Se 3 (x = 0.87-1.05) compounds when the composition changed from a Cu-to a Sn-rich one.…”

“…[43][44][45] Xi et al studied the effects of doping on the TE properties of Cu 2 SnS 3 and Cu 2 SnSe 3 , found the regime where the best performance was realized, and estimated the maximum ZT of Cu 2 SnS 3 and Cu 2 SnSe 3 . 43 Yang et al synthesized Cu 2 ZnSnS 4 nanocrystals and achieved a ZT value of 0.14 at 700 K. 44 Fan et al studied the thermoelectric properties of Cu 3Àx Sn x Se 3 (x = 0.87-1.05) compounds when the composition changed from a Cu-to a Sn-rich one. 45 However, there has been little research on the TE properties of these diamond-like semiconductors using first-principles calculations.…”