Malik Zahida, Kemp Liam, Grosso Bastien F, Davies Daniel W, Scanlon David O, Hyett Geoffrey
School of Chemistry and Chemical Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Highfield Campus, Southampton SO17 1BJ, U.K.
School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
Chem Mater. 2024 Nov 14;36(22):11326-11337. doi: 10.1021/acs.chemmater.4c02760. eCollection 2024 Nov 26.
The structural, electrical, and optical properties of a series of six layered oxychalcogenides with the general formula Sr OCu, where M = Ga, Sc, or In and = S or Se, have been investigated. From this set, we report the structure and properties of SrGaOCuSe for the first time, as well as the full structural details of SrScOCuSe, which have not previously been available. A systematic study of the suitability of all of the Sr OCu phases as -type conductors has been carried out, after doping with both sodium and potassium to a nominal composition of Sr OCu, ( = Na or K), to increase the hole carrier concentration. Density functional theory calculations were used to determine the electronic band structure and predict the transport properties, while optical properties were determined using UV-vis spectroscopy, and structures were confirmed using Rietveld refinement against powder X-ray diffraction data. Room-temperature conductivity measurements were carried out on both pristine samples and doped samples, 18 compositions in total, using four-point probe measurements. We found that the most conductive sample was KSrGaOCuSe, with a measured conductivity of 0.46 S cm, collected from a sintered pellet. We have also been able to identify a relationship between the conductivity and the geometry of the copper chalcogenide layer within the Sr OCu series of compounds. As this geometry can be controlled through the material composition, the identification of this structure-property relationship highlights a route to the selection and identification of materials with even higher conductivities.
对一系列通式为Sr₂MO₂Cu₂（其中M = Ga、Sc或In，X = S或Se）的六层氧硫属化物的结构、电学和光学性质进行了研究。在这一系列化合物中，我们首次报道了SrGa₂OCu₂Se的结构和性质，以及SrSc₂OCu₂Se完整的结构细节，这些细节以前未曾有过。在将钠和钾掺杂到名义组成为Sr₂MO₂Cu₂（M = Na或K）以增加空穴载流子浓度之后，对所有Sr₂MO₂Cu₂相作为p型导体的适用性进行了系统研究。利用密度泛函理论计算来确定电子能带结构并预测输运性质，同时使用紫外可见光谱法测定光学性质，并利用Rietveld精修粉末X射线衍射数据来确认结构。使用四点探针测量法对总共18种组成的原始样品和掺杂样品在室温下进行电导率测量。我们发现导电性最强的样品是KSrGa₂OCu₂Se，从烧结颗粒测得的电导率为0.46 S/cm。我们还能够确定Sr₂MO₂Cu₂系列化合物中电导率与硫属化铜层几何结构之间的关系。由于这种几何结构可以通过材料组成来控制，这种结构-性质关系的确定突出了一条选择和鉴定具有更高电导率材料的途径。
