Spin chiral interactions modulated Seebeck coefficient and improved optical properties by Zn doping in CuCrO2 crystallites

• Published in: Materials chemistry and physics 2023-10, Vol.308, p.128214, Article 128214
• Main Authors: Jamshina Sanam, P.K., Gopika, K.G., Pradyumnan, P.P.
• Format: Article
• Language: English
• Subjects: Optical properties; Raman spectroscopy; Spin chirality; Thermoelectric properties; X-ray diffraction
• ISSN: 0254-0584
• DOI: 10.1016/j.matchemphys.2023.128214

Future electronics hold a special promise for flexible, optically translucent thermoelectric devices. Here, we demonstrate the better thermoelectric per-formance of p-type transparent CuCrO2 crystallites by the insertion of non-magnetic Zn2+ in magnetic Cr3+ site at room and high temperatures. Dop-ing-induced increase in charge carrier density generally leads to elevated car-rier scattering, which in turn diminishes the voltage generated per unit tem-perature difference and causes a decrease in the Seebeck coefficient. Balancing the Seebeck coefficient and conductivity is a crucial challenge in the design of thermoelectric materials. By introducing magnetic doping, the antifer-romagnetic order of Cr3+ ions is destabilized, resulting in a modification of the spin configuration. This alteration gives rise to spin chiral interactions, which, in turn, contribute to the generation of an exceptionally large Seebeck coefficient of 582 μV/K at 100 °C. The insertion also generates anisotropic microstrains in the structure and the structural changes were investigated by XRD analysis, FTIR, and Raman spectroscopy. Carrier concentration and carrier mobility were measured by Hall measurements techniques and has shown increasing and decreasing trend respectively with the increase of the doping percentage of Zn2+. Optical studies were done by UV–Vis analysis and found the maximum band gap of 3.04 eV for 0.5 wt% doped CuCrO2 and the absorption spectra revealed the defect induced in the structure com-prehending the Raman analysis. The enhancement of carrier concentration and mobility led to increased conductivity of 2096 S/m and power factor of 411 μW/mK2 for the sample 0.3 wt% at 700 °C. The Seebeck coefficient of the sample dropped as the temperature rose, but it was maintained in the range of 440–580 μV/K, which is found as the primary characteristic of Zn doping. Thermal conductivity is found as decreased with doping and the highest ZT obtained is 0.199 for 0.3 wt% doped sample at 700 °C. The higher thermoelectric performance and optical transmission at visible wavelength can be put together in optoelectronic devices. •Energy generation by TE is a technique for the production of electricity without any moving parts.•CuCrO2 compounds are best known for their optoelectronic as well as thermoelectric (TE) properties.•Optimizing electrical transport property, carrier concentration and effective mass is an effective way to improve power factor.•The Seebeck coefficient of th