Direct observation of a two-dimensional hole gas at oxide interfaces
Source abstract
Abstract
The discovery of a two-dimensional electron gas (2DEG) at the LaAlO3/SrTiO3 interface 1 has resulted in the observation of many properties2-5 not present in conventional semiconductor heterostructures, and so become a focal point for device applications6-8. Its counterpart, the two-dimensional hole gas (2DHG), is expected to complement the 2DEG. However, although the 2DEG has been widely observed 9 , the 2DHG has proved elusive. Herein we demonstrate a highly mobile 2DHG in epitaxially grown SrTiO3/LaAlO3/SrTiO3 heterostructures. Using electrical transport measurements and in-line electron holography, we provide direct evidence of a 2DHG that coexists with a 2DEG at complementary heterointerfaces in the same structure. First-principles calculations, coherent Bragg rod analysis and depth-resolved cathodoluminescence spectroscopy consistently support our finding that to eliminate ionic point defects is key to realizing a 2DHG. The coexistence of a 2DEG and a 2DHG in a single oxide heterostructure provides a platform for the exciting physics of confined electron-hole systems and for developing applications.
Source: europepmc · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Electronic and Structural Properties of Oxides · Magnetic and transport properties of perovskites and related materials · Semiconductor materials and devices
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (43)
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