Design of ternary alkaline-earth metal Sn(ii) oxides with potential good p-type conductivity. Issue 20 (25th April 2016)

• Record Type: Journal Article
• Authors: Li, Yuwei; Singh, David J.; Du, Mao-Hua; Xu, Qiaoling; Zhang, Lijun; Zheng, Weitao; Ma, Yanming
• Is Part Of: Journal of materials chemistry. Volume 4:Issue 20(2016)
• Page Start: 4592
• Page End: 4599
• Publication Date: 2016-04-25
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c6tc00996d
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Novel ternary alkaline-earth metal Sn(ii ) oxides with potential good p-type conductivity are discovered with first-principles global optimization structure searches. Abstract : Oxides with good p-type conductivity have been long sought after to achieve high performance all-oxide optoelectronic devices. Divalent Sn(ii ) based oxides are promising candidates because of their rather dispersive upper valence bands caused by the Sn-5s/O-2p anti-bonding hybridization. There are so far few known Sn(ii ) oxides being p-type conductive suitable for device applications. Here, we present via first-principles global optimization structure searches a material design study for a hitherto unexplored Sn(ii )-based system, ternary alkaline-earth metal Sn(ii ) oxides in the stoichiometry of MSn2 O3 (M = Mg, Ca, Sr, Ba). We identify two stable compounds of SrSn2 O3 and BaSn2 O3, which can be stabilized by Sn-rich conditions in phase stability diagrams. Their structures follow the Zintl behaviour and consist of basic structural motifs of SnO3 tetrahedra. Unexpectedly they show distinct electronic properties with band gaps ranging from 1.90 (BaSn2 O3 ) to 3.15 (SrSn2 O3 ) eV, and hole effective masses ranging from 0.87 (BaSn2 O3 ) to above 6.0 (SrSn2 O3 ) m 0 . Further exploration of metastable phases indicates a wide tunability of electronic properties controlled by the details of the bonding between the basic structural motifs. This suggests further exploration of alkaline-earth metal Sn(ii ) oxides for potential applications requiring good p-type conductivity such as transparent conductors and photovoltaic absorbers.