Photocurrent spectroscopy of ${\mathrm{Zn}}_{1\mathrm{-}\mathit{x}}$${\mathrm{Cd}}_{\mathit{x}}$Se/ZnSe quantum wells in p-i-n heterostructures

Photocurrent-spectroscopy studies were performed in the 10<T<300 K temperature range on p-i-n heterostructures grown by molecular-beam epitaxy and incorporating ${\mathrm{Zn}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{Cd}}_{\mathit{x}}$Se/ZnSe multiple quantum wells (with x=0.10 and 0.25) in the undoped region. The extremely well-resolved excitonic features and corresponding continuum edges allowed us to obtain directly the exciton binding energies and compare the spectra with excitonic transition energies calculated taking into account the effect of strain.