Room-Temperature Silicon Band-Edge Photoluminescence Enhanced by Spin-Coated Sol-Gel Films

TL;DR

This study demonstrates enhanced room-temperature silicon photoluminescence through spin-coated Er-doped silica-gel films, revealing a two-orders magnitude increase in emission efficiency due to stress-induced mechanisms.

Contribution

It introduces a novel method of enhancing silicon photoluminescence using spin-coated Er-doped sol-gel films and analyzes the underlying stress-induced mechanisms.

Findings

Two-orders of magnitude increase in emission efficiency.

Optimal annealing temperature around 700°C.

Correlation between Er ion emission and silicon photoluminescence.

Abstract

Photoluminescence is observed at room temperature from phonon-assisted band-to-band emission in Si (1.067 eV peak) using unpatterned bulk p-type silicon wafer samples that were spin-coated with Er-doped (6 at. %) silica-gel films (0.13 micron) and vacuum annealed; the strongest emission was obtained at ~700 degrees C. Comparative study of annealing behavior indicates two-orders of magnitude efficiency enhancement. Emission from Er+3 ions in the silica film is used to gauge relative emission strengths. Mechanisms for inducing emission from silicon utilizing stresses in sol-gel-films are discussed.