Temperature Dependence of Band Gap Change in InN and AlN

The optical band gap of InN and AlN single crystal films was measured through absorption spectra in the temperature range of 4.2 to 300 K. The samples were grown on (0001)α-Al 2 O 3 substrates by metalorganic vapor phase epitaxy. The Varshni equation and the Bose-Einstein expression have been compared with the experimental results. The nitride III-V compound semiconductors have smaller temperature dependence of band gap change. In III-V compound semiconductors, the variation of the band gap change increases in the order of N, P and As.