Centennial Honors College
Western Illinois University
Undergraduate Research Day 2014
Poster Presentation
Measuring the optical band gap of varying composition Lead-Borate glasses with
Cadmium-Selenide nanoparticles
Nicholas Breslin
Faculty Mentors: P. K. Babu and Saisudha B. Mallur
Physics
Nanomaterials have different physical properties than their macroscopic counterparts.
One of the properties that vary among nanomaterials is their optical properties. By
varying the composition of the lead borate glasses and semiconducting nanomaterials
we can witness the changes of the optical band gap. In this lab we created glasses of a
general composition (x%)PbO-(99-x%)B2O3-(1%)CdSe with PbO ranging between 39%69%). The samples were made by melting the compound in a box furnace at 950ºC
and then were quenched and annealed for one hour in a tube furnace at 400ºC to
remove thermal strains. These glasses were then smoothened and polished on a lapper
machine. The polished samples were taken to a Cary 500 UV-VIS Spectrophotometer
to measure optical absorption of the samples in a range from 300nm-900nm to find the
optical band gap by analyzing the optical edge of the samples