Influence of lattice mismatch on properties of InxGa1−xAs1−yPy layers epitaxially grown on InP substrates

Abstract

Minority carrier (electron) diffusion length, density of electron traps and surface morphology in In_xGa_1−xAs_1−yP_y LPE layers grown on InP substrates have been investigated as a function of layer/substrate lattice mismatch. Two kinds of electron traps at E_c−0.60 and 0.67 eV are detected by DLTS measurement in undoped n‐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 in p‐type layers (x = 0.84,y = 0.63 at the lattice match condition) with the hole density ranging from 1 to 5×10¹⁷ cm⁻³ is almost independent of the amount of lattice mismatch at least within ±0.4 %. This result is explained in terms of dominant direct recombination process.