Mechanisms of luminescence tuning and quenching in porous silicon

• Published in: Thin solid films Vol. 276; no. 1-2; pp. 123 - 129
• Main Authors: Peter, L.M, Riley, D.J, Wielgosz, R.I, Snow, P.A, Penty, R.V, White, I.H, Meulenkamp, E.A
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 15.04.1996; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electrochemistry; Exact sciences and technology; Luminescence; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Photoluminescence; Physics; Porous materials; Silicon; Electrochemistry; Silicon; Luminescence; Particle size; Porous materials; Photoluminescence; Electroluminescence; Experimental study; Quenching; Thin films; Anisotropy; Optical properties; Kinetics
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/0040-6090(95)08039-2

Voltage-dependent tuning of photoluminescence (PL) and electroluminescence (EL) spectra of porous silicon layers grown on n+ and n− substrates has been studied using electrolyte contacts. It has been demonstrated that PL and EL tuning occur under accumulation conditions. A mechanism that explains both PL and EL tuning is proposed on the basis of a kinetic; “scheme of squares” that considers incremental electron injection into quantum-confined particles, leading to Auger quenching of photoexcited or electrochemically generated electron-hole pairs. The tuning effects are predicted to occur as a consequence of the dependence of electron accumulation on the energy of the conduction band, which is turn related to particles size. PL and EL spectra have been simulated for an ensemble of particles of different sizes, and it is shown that the model correctly predicts all the experimentally observed characteristics of the voltage tuning.