Study On The Interfcial Electrical Properties Of LaAlO₃/GaAs Heterojunction

Functional oxides have attracted considerable research attention due to their wide properties:ferromagnetism,ferroelectricity,piezoelectricity,thermoelectricity,superconductivity,and nonlinear optical effects.The III-V semiconductor substrate has special application significance due to its good optoelectronic and high mobility transport properties.The integration of functional oxides on III-V semiconductor substrates is a hotspot in the current study.The STO/GaAs interface with high carrier mobility is a typical example.LaAlO₃ and SrTiO₃ are both perovskite-type oxides,and their lattice sizes are very close.Based on the lattice relationship between bismuth aluminate and strontium titanate,this article focuses on the study of the electrical properties of the lanthanum aluminate/aluminum gallium arsenide?LAO/GaAs?heterointerface,and mainly completes the following work:1.High quality thin film sample of LAO/GaAs was fabricated with GaAs?100?as the substrate and LAO as the target by Using pulsed laser deposition?PLD?equipment.2.XRD characterization of LAO/GaAs samples confirms that the growth orientation of LAO is in the direction of the expected GaAs diagonal.3.Temperature-varying Hall test of the electrical transport properties of the LAO/GaAs interface shows that the LAO/GaAs interface has higher hole-type carrier mobility.4.The first-principles calculations were introduced to establish a lattice structure model at the LAO/GaAs interface and the density of states was analyzed.It is suggested that the higher carrier mobility at the LAO/GaAs interface is most probably caused by oxygen vacancies at the interface.