Synthesis of Wurtzite Cu₂ZnGeSe₄ Nanocrystals and their Thermoelectric Properties

Abstract

An unusual wurtzite phase of Cu2ZnGeSe4 (CZGSe) has been discovered and its corresponding nanocrystals (NCs) were synthesized by using a facile hot-injection solution-phase synthesis method. Moreover, the formation mechanism of this new phase of CZGSe, instead of the typically observed stannite structure, has been investigated in detail, which indicates that wurtzite CZGSe, which represents the kinetic phase, could be prepared by using a kinetic growth process without phase transformation into the thermodynamically stable stannite structure during the colloidal synthesis. In addition, the potential of wurtzite CZGSe as a thermoelectric material is demonstrated by characterizing the thermoelectric properties of as-synthesized wurtzite CZGSe NCs. This work allows for a rational manipulation of the NCs with a desired crystal structure through adjusting the thermodynamics and kinetics without using any additives and, because of its simplicity and versatility, it may be extended to the phase-controlled synthesis of other chalcogenide NCs.

Investigation of Physical and Electronic Properties of GeSe for Photovoltaic Applications

“…[11][12][13][14] Additionally, the congruent sublimation feature of GeSe makes it ideal for thin film deposition through thermal sublimation, entirely compatible with conventional processing methods for CdTe thin-film solar cells. [15] All the aforementioned features merit its exploration for photovoltaic applications.…”

Heterovalent Substitution to Enrich Electrical Conductivity in Cu2CdSn1-xGaxSe4 Series for High Thermoelectric Performances

“…The reported ZT values for pure polycrystalline are 0.19 for Cu 2 CdSnSe 4 and 0.18 for Cu 2 ZnSnSe 4 4. Many efforts have been done to enhance the TE performance of these quaternary compounds by doping1467891011 and nanocrystalling3512131415161718. Nanocrystallization is an effective way to reduce the thermal conductivity, but the complex chemical procedure is not suitable for large scale production in commercial applications.…”

Multifunctional Copper‐Based Quaternary Chalcogenide Semiconductors Toward State‐of‐the‐Art Energy Applications

“…Not just chalcopyrite type quaternary chalcogenides, but the other structural forms of these quaternary chalcogenides such as wurtzite, orthorhombic, stannite and stannite‐kuramite etc. have been explored in the recent times ,,,. There is a possibility that random distribution of cations and anions in the unit cell gave rise to structural anisotropy which is responsible for lowering thermal conductivity in such material.…”