Influence of lattice mismatch on properties of InxGa1minus;xAs1minus;yPylayers epitaxially grown on InP substrates

摘要

Minority carrier (electron) diffusion length, density of electron traps and surface morphology in InxGa1minus;xAs1minus;yPyLPE layers grown on InP substrates have been investigated as a function of layer/substrate lattice mismatch. Two kinds of electron traps atEcminus;0.60 and 0.67 eV are detected by DLTS measurement in undopednhyphen;type layers (x= 0.77,y= 0.65). Their density is very sensitive to the amount of lattice mismatch. On the contrary, the electron diffusion length inphyphen;type layers (x= 0.84,y= 0.63 at the lattice match condition) with the hole density ranging from 1 to 5times;1017cmminus;3is almost independent of the amount of lattice mismatch at least within plusmn;0.4 percnt;. This result is explained in terms of dominant direct recombination process.