2012 journal article

On the origin of the 265 nm absorption band in AlN bulk crystals

APPLIED PHYSICS LETTERS, 100(19).

By: R. Collazo n, J. Xie*, B. Gaddy n, Z. Bryan n, R. Kirste n, M. Hoffmann n, R. Dalmau*, B. Moody* ...

co-author countries: Japan 🇯🇵 United States of America 🇺🇸
Source: Web Of Science
Added: August 6, 2018

Single crystal AlN provides a native substrate for Al-rich AlGaN that is needed for the development of efficient deep ultraviolet light emitting and laser diodes. An absorption band centered around 4.7 eV (∼265 nm) with an absorption coefficient above 1000 cm−1 is observed in these substrates. Based on density functional theory calculations, substitutional carbon on the nitrogen site introduces absorption at this energy. A series of single crystalline wafers were used to demonstrate that this absorption band linearly increased with carbon, strongly supporting the model that CN- is the predominant state for carbon in AlN.