Computationally Guided Discovery of Semiconductors with Axis Dependent Conduction Polarity - "Goniopolar" Materials
Abstract
The overall goal of this proposal is to combine theory, synthesis and property characterization to create new families of semiconducting goniopolar materials materials that can simultaneously conduct n-type and p-type carriers along orthogonal crystallographic axes. In most modern electronic materials and devices, a single material is optimized to exhibit a single kind of electronic behavior, either metallic or semiconducting that is doped to exhibit a majority carrier type. However, many crystal lattices that feature anisotropic bonding along different directions, such as layered or chain-like frameworks can exhibit completely different band curvatures within the layer or chain axes and orthogonal to them. With the ideal band curvatures, this can lead to electron and hole mobility tensors that are orders of magnitude higher along different axes, and thus simultaneous electron and hole conduction along these orthogonal directions, when both carrier types are present. Our aims are to combine computational predictions, single crystal synthesis and axis-dependent measurements to a) Understand the origin of axis-dependent conduction polarity in Re4Si7 which is currently the only known goniopolar semiconductor as well as predict and experimentally confirm new families of b) narrow band bap goniopolar semiconductors (Egap < 0.4 eV) andwide band gap goniopolar semiconductors (Egap > 0.4 eV). We proposed to search for goniopolarity in the 1:1:1 copper group AMX compounds (i.e. CaCuP, BaCuP), the Nowotny chimney ladder phases, and layered Zintl phase intermetallics to have 1:1:1 stoichiometry. Over the course of this project we have established the key band structure fingerprints for goniopolar materials, more than doubled the number of known goniopolar compounds, and have demonstrated their potential in a variety of applications.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 19, 2022
- Accession Number
- AD1231210
Entities
People
- Joshua E Goldberger
- Wolfgang Windl
Organizations
- Ohio State University