An artificial nonradiative recombination center model created by use of a Si1 − xGex/Si quantum-well-inserted pseudomorphic superlattice

An attempt is made to mimic a system under the influence of nonradiative recombination (NR) by use of a Si_1 − xGe_x quantum well (QW) embedded in a Si_1 − xGe_x/Si strained-layer superlattice. Carrier transfer mediates the coupling between the first miniband of superlattice barrier and QW ground state, which is useful in setting up an artificial NR center based only on radiative channels. Steady-state and transient photoluminescence (PL) reproduces spectroscopic features shared by NR systems at large such as quadratic dependence of PL intensity on excitation power and prolonged decay time at increased pumping, which are quite opposite to radiative recombination.