Work

Giant polarization charge density at lattice-matched GaN/ScN interfaces

Year: 2019

Type: article

Abstract: Rock-salt ScN is a semiconductor with a small lattice mismatch to wurtzite GaN. Within the modern theory of polarization, ScN has a nonvanishing formal polarization along the [111] direction. As a result, we demonstrate that an interface between (0001) GaN and (111) ScN exhibits a large polarization discontinuity of −1.358 Cm−2. Interfaces between ScN and wurtzite III-nitrides will exhibit a high-density electron gas at the (0001¯) GaN interface or a hole gas at the (0001) GaN interface, with carrier concentrations up to 8.5×1014 cm−2. The large polarization difference and small strain make ScN a desirable choice for polarization-enhanced tunnel junctions within the III-nitride materials system. The large sheet carrier densities may also be useful for contacts or current spreading layers.

Source: Applied Physics Letters

DOI: 10.1063/1.5126717

Authors: Nicholas L. Adamski, Cyrus E. Dreyer, Chris G. Van de Walle

Institutions: University of California, Santa Barbara, Simons Foundation, Flatiron Institute, Stony Brook University

Language: English

Topic: GaN-based semiconductor devices and materials

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, U.S. Department of Defense, Air Force Office of Scientific Research

Awards: G1110399006, G3226045097, G4347266479, Materials Research Science and Engineering Center at UCSB