Disorder of an Al<i>x</i>Ga1−<i>x</i>As-GaAs superlattice by donor diffusion

Abstract

The Si impurity is diffused (850 °C, 10 h, xj ∼2.4 μm) into 2.4 μm of AlxGa1−xAs-GaAs (x≳0.6) superlattice (barrier LB ≊320 Å, quantum well Lz ≊280 Å) and disorders it into bulk-crystal Alx′Ga1-x′As (x′≳0.32). The as-grown infrared gap superlattice is converted selectively to red gap bulk crystal and, where undiffused and not disordered, is still capable of continuous 300-K photopumped laser operation at a threshold of 4×103 W/cm2 (or Jeq ∼1.7×103 A/cm2, 5145 Å pump photon).