Electrical Properties Of Indium Arsenide Under High Pressure

Indium arsenide(InAs)is a very important III-V semiconductor material,with high electron mobility and high electron transport velocity.In the domain of defense communications has a strong application.In our paper,we integrated the film deposition with photolithographic technique to fabricate a microcircuit on the diamond anvil cell(DAC),We conducte in situ the resistivity measurement experiment and hall-effect measurement on InAs under high pressure and analyze these properties of InAs sample by using first-principles calculations,the micro-mechanism of structural phase transition and metallization.Study results are listed as follow:We conducte in situ the resistivity measurement experiment on InAs under high pressure.In the compression process,the changing curve of the resistivity with the pressure increasing occurs five discontinuous changes,which were 3.8 GPa,7.2 GPa,10.3 GPa,11.7 GPa and 16.0 GPa.Among them the resistivity shows a mutation at 7.2 GPa and 16.0 GPa,at which have been reported.And 3.8 GPa,10.3 GPa and 11.7 GPa resistivity discontinuities were found for the first time,We did not find the phenomenon of resistivity mutation on the third phase change at 18.0 GPa.In order to resolve the dispute of metalization,we carried out in situ the tem-perature dependence of the resistivity measurement experiment on InAs under high pressure.When the pressure is less than 3.8 GPa,the resistivity of InAs shows a negative reationship with temperature increasing,indicating that InAs is asemi-conductor.Above 3.8 GPa,the resistivity increases with temperature increasing,indicating InAs transformation metallized arround this pressure.By carrieding out in situ Hall-effect measurement experiment on In As under high pressure,we obtained the pressure dependences of Hall coefficient,carrier con-centration and mobility.Increasing the carrier concentration(n)leads to a decrease in the resistivity of the sample at the range from 0 GPa to 7.2 GPa.At the range of 7.2 GPa to 10.3 GPa the carrier mobility(u)continues to increase as the main factor affecting the resistivity of the sample.With the pressure rising,the hall coefficient of In As increases and changes its sign to positive at 10.3 GPa.That indicates In As transforming into n-type semiconductor from p-type around 10.3 GPa.The charge transport is converted from electron conduction to hole conduction.The band gap widens with the increases of pressure,causing the carrier concentration(n)to de-crease and the carrier mobility(?)increases,resulting in a decrease in resistivity.The first-principles calculations of InAs sample:the F43m phase transforms into the Fm3m phase at 12.0 GPa from the changing enthalpy vs.pressure relation-ships and the Fm3m phase transforms into the Cmcm phase at 16.0 GPa.The once phase transition occurred 16.9%of the volume collapse,the second phase transition occurred 0.7%of the volume collapse.The band structure shows that the sample conduction band passes through the Fermi level and overlap with the valence band after 3.8 GPa,which indicates that the InAs sample has metalized.