The effect of combined doping by shallow donor and acceptor impurities in boosting the quantum yield of porous-Si photoluminescence in the visible and near-infrared ranges was studied using P and B ion implantation. Non-uniform doping of samples and subsequent oxidizing annealing were performed before and after porous Si was formed on Si single crystals strongly doped with As or B to up to some 1019/cm3. The concentration of known Pb centers of non-radiative recombination was controlled by electron paramagnetic resonance. It was shown that there was an optimal joint content of shallow donors and acceptors that provided maximum photoluminescence intensity in the vicinity of the red part of the visible spectrum. It was estimated that the photoluminescence quantum yield in the transitional n++-p+ or p++-n+ layer of porous Si increased by 2 orders of magnitude as compared to that in porous Si formed on Si not subjected to ion bombardment.

Photoluminescence and EPR of Porous Silicon Formed on n+ and p+ Single Crystals Implanted with Boron and Phosphorus Ions. E.S.Demidov, I.S.Rassolova, O.N.Gorshkov, V.K.Vasilev, M.O.Marychev, A.N.Mikhaĭlov, D.I.Tetelbaum, S.A.Filippov: Physics of the Solid State, 2008, 50[8], 1565-9