Photoluminescence from heavily doped Si layers grown by liquid-phase epitaxy

Abstract

Heavily phosphorus or gallium-doped silicon was grown by liquid-phase epitaxy and studied by photoluminescence. For the phosphorus-doped samples grown from In(P) solution, recombination of free electrons to compensating In acceptor levels was observed besides the free electron-free hole band-to-band emission. The gallium-doped samples showed a luminescence spectrum similar to the one observed in bulk-doped p-type material, indicating a good crystalline quality and low compensation in these samples. The band-gap shrinkage was found to be larger in heavily gallium-doped than in boron-doped silicon, indicating a dependence of this shrinkage on the chemical nature of the dopant atoms.