A Study of the Optical Bandgap Energy and Urbach Energy Tail of Two White A4 Copy Paper Samples

Two white Α4 copy paper samples Q-Connect and Laser Copy were tested for the fiber component of their pulps using the optical microscope and were determined as chemical pulps. UV-VIS data revealed the values of Urbach energies of 498.2meV and 498.1meV of the two copy paper samples respectively, when the thickness of both samples was d=1mm. The value of indirect bandgap energy was calculated to be 1.16984469010026eV for Q-Connect copy paper sample, and 1.1698449010027eV respectively, with the Laser Copy paper sample. The Urbach energy of the A4 copy paper sample Q-Connect was calculated to be 333.7meV when its thickness was d=0.101mm whereas the Urbach energy of the A4 copy paper sample Laser Copy was calculated to be 330.2meV when its thickness was d=0.094mm. A decrease in Urbach energy with a decrease in thickness from 101μm to 94μm, and an increase in energy band gap, were observed for the two copy paper samples, respectively.