Conductionband offsets in pseudomorphic In_{x}Ga_{1x}As/Al_{0.2}Ga_{0.8}As quantum wells (0.07<=x<=0.18) measured by deeplevel transient spectroscopy
Abstract
The variation of the potential of a quantum well is similar to that of a deep trap. In that respect a quantum well can capture and emit carriers in much the same way as a trap. The thermal emission energy from a quantum well is closely related to the appropriate band offset. With that in mind, we have carried out deeplevel transient spectroscopy measurements on Schottkybarrier diodes containing one or more pseudomorphic In_{x}Ga_{1x}As/Al_{0.2}Ga_{0.8}As (0<x<=0.18) quantum wells. The objective was to estimate the conductionband offset, ∆E_{c}, as a function of x and the resulting strain. From detailed balance between emission and capture, an Arrheniustype expression was derived to analyze the transient emission data. It is seen that the percentage band offset ∆E_{c}/∆E_{g} varies from 62% for x=0.07 to 70% at x=0.18. Furthermore, a linear interpolation of the data leads to ∆E_{c}/∆E_{g}=58% at x=0, which is close to the widely accepted value. Our results support recent theoretical calculations from which a monotonic increase in ∆E_{c} with strain in this heterostructure system is predicted.
 Publication:

Physical Review B
 Pub Date:
 July 1989
 DOI:
 10.1103/PhysRevB.40.1058
 Bibcode:
 1989PhRvB..40.1058D
 Keywords:

 73.40.Kp;
 73.20.Dx;
 IIIV semiconductortosemiconductor contacts pn junctions and heterojunctions