Abstract
We report that the electron cooling time in indium nitride can be as fast as sub-100 femtosecond at low electron concentration (<5× 10 <sup>17</sup> cm <sup>3</sup> ), which is much faster than previous reports. Through investigating the dependence of the measured carrier cooling time on electron density, our study proved the dominant role of the screened Fröhlich interaction in the reduction in carrier cooling rate at an electron density higher than 1.8× 10 <sup>18</sup> cm <sup>3</sup> . © 2010 American Institute of Physics.