Comparative Study on Electronic, Emission, Spontaneous Property of Porous Silicon in Different Solvents

Abstract

Luminescent porous silicon (Psi) fabricated by simple chemical etching technique in different organic solvents was studied. By quantifying the silicon wafer piece, optical properties of the Psi in solutions were investigated. Observation shows that no photoluminescence light of Psi in all solvents is emitted. Morphology of Psi in different solvents indicates that the structure and distribution of Psi are differently observed. Particles are uniformly dispersive with the sizes around more or less 5–8 nm. The crystallographic plane and high crystalline nature of Psi is observed by selected area diffraction (SED) and XRD. Electronic properties of Psi in solutions are influenced due to the variation of quantity of wafer and nature of solvent. Influence in band gaps of Psi calculated by Tauc’s method is obtained due to change of absorption edge of Psi in solvents. PL intensities are observed to be depending on quantity of silicon wafer, etched cross-section area on wafer surface. Effects on emission peaks and bands of Psi under temperature annealing are observed. The spontaneous signals of Psi measured under high power Pico second laser 355 nm source are significant, influenced by the nature of solvent, pumped energy, and quantity of Si wafer piece used in etching process.

The Role of Solvent Environment on the Optical Behavior of Chemically Synthesized Silicon Nanoparticles

“…The possibility of high luminescent efficiency in unaprotic solvents is because they are not containing the O-H functional groups, which help in emitting light of Si-NPs in solvent with stability since aprotic solvents do not contain such functional groups. The Si-NPs exhibit good luminescence spectra in some nonpolar solvents but its stability is very limited [18]. It can be easily discerned from Figure 3 that the absorption band shape and peak maxima of Si-NPs in different solvents are increasing with polarity index and dielectric constant.…”

“…The etched 3 Journal of Spectroscopy surface area may vary in wafer piece to piece because of the nonuniformity etching in HF-based etching solution. The larger etched area of wafers may produce greater quantity of particles in solvents [18].…”

“…Previously, some coworkers in our laboratories studied the emission spectra that Si-NPs fabricated by chemical etching technique in different organic solvents [12,18,19]. They examine the effects of solvents and temperature on the optical absorption spectra and luminescence spectra of Si-NPs, in which the emission and absorption properties of Si-NPs were tuned by altering the environment (solvents) because of electrostatic interaction of various organic solvents with Si-NPs [19].…”

Mixed bismuth‐antimony‐based double perovskite nanocrystals for solar cell application

“…Two PL peaks at 528 and 547 nm (direct and indirect bandgap) in Cs 2 AgBiBr 6 ‐based perovskite NCs are observed. The effect of solvent on emission spectra is complex, and in addition to solvent polarity, it is due to several other factors 41 . The factors affecting the emission spectra and quantum yields include solvent polarity, viscosity, solvent relaxation rate, probe conformational changes, the rigidity of the local environment, internal charge transfer, proton transfer, excited‐state reaction, probe‐probe interaction, and change in radiative/nonradiative decay rates.…”

Advanced In Situ I-V Measurements Used in the Study of Porous Structures Growth on Silicon

“…The macropores are easily seen by means of a microscope. This is not the case of nanopores, so an ultraviolet (UV) lamp illumination, UV excited photoluminescence, was used in order to prove the existence of nanopores [18][19][20]. Here, it is important to note difficulty in differentiating between mesopores and nanopores, but mesopores are expected to exist on the transition from macropores to nanopores.…”