Determination of the conduction‐band discontinuity between In0.53Ga0.47As/In0.52Al0.48As using n+‐InGaAs/InAlAs-‐InGaAs capacitors

摘要

The conduction‐band discontinuity (ΔEc) between In0.53Ga0.47As and In0.52Al0.48As is determined by current‐voltage measurements on n+‐InGaAs/InAlAs-‐InGaAs capacitors. Current is found to be dominated by thermionic emission conduction down to 180 K. Barrier heights are determined from the slope of ln(J/T2) vs 1/T where good straight‐line fits are obtained in the thermionic emission range. After correcting for the Fermi level a conduction‐band discontinuity of 0.51±0.04 eV is obtained representing 70% of the total band‐gap discontinuity. Furthermore, capacitance‐voltage measurements are fit to classical capacitance‐voltage theory and show that no charge is present in the InAlAs insulating layer.