Effect of Phosphorus Doping on Photoinduced Thermal Processes in Silicon Nanowires

Abstract

We report on the effect of phosphorus doping of silicon nanowires (SiNWs) on the photoinduced heating processes. SiNWs samples were prepared by metal-assisted chemical etching of low boron-doped crystalline silicon (c-Si) wafers followed with thermo-diffusional doping with phosphorous (P) up to 1020 cm-3. We establish that the P-doping (n-type) results in effective heat conduction along SiNWs toward the c-Si substrate during laser heating. Partial phase transition in P-doped SiNWs under intense photoheating was detected by means of Raman spectroscopy and photoluminescence. The observed doping effects were explained by a contribution of charge carriers (electrons) to the heat distribution along SiNWs and partial screening of the crystal lattice potential. The obtained results can be useful for the development of new photonic and optoelectronic devices based on SiNWs.