Temperature dependence of photoluminescence of InGaN films containing In-rich quantum dots

The temperature dependence of the photoluminescence (PL) of InGaN films, gr own by metalorganic chemical vapor deposition, has been investigated. A str ained InGaN thin film which contains composition-fluctuated regions shows t he so-called S-shaped temperature dependence of the dominant PL peak energy . However, an InGaN thick film which contains quantum dot-like In-rich regi ons shows a sigmoidal temperature dependence of the dominant PL peak energy , as the result of a transfer of carriers from the band-edge related lumine scent centers to quantum dot-like In-rich regions. It is also found that th e activation energy for the thermal quenching of PL intensity in the InGaN thick film which contains quantum dot-like In-rich regions is larger than t hat in the strained InGaN thin film which contains composition-fluctuated r egions. (C) 2001 American Institute of Physics.