摘要
Indium-composition fluctuations in InGaN epitaxial layers are suppressed by using periodically-pulsed mixture(PPM)of N2and H2carrier gas. Photoluminescence, optical transmission, reciprocal space map and space-resolved cathodoluminescence are employed to characterize the InGaN epilayers. It is shown that the lateral In-fluctuations mainly occur as hillock-like In-rich regions. Both the number and size of In-rich regions are reduced by introducing the PPM carrier gas.Moreover, the measurements first experimentally demonstrate that the H2carrier gas has a stronger decomposition effect on the In-rich region. As the duration time of the PPM carrier gas increases, the reduction of In-content in the In-rich region reaches up to 12%, however, only 2% for the In-homogeneous region. These factors lead to the suppression of In-fluctuations.
Indium-composition fluctuations in InGaN epitaxial layers are suppressed by using periodically-pulsed mixture(PPM)of N_2 and H_2 carrier gas. Photoluminescence, optical transmission, reciprocal space map and space-resolved cathodoluminescence are employed to characterize the InGaN epilayers. It is shown that the lateral In-fluctuations mainly occur as hillock-like In-rich regions. Both the number and size of In-rich regions are reduced by introducing the PPM carrier gas.Moreover, the measurements first experimentally demonstrate that the H_2 carrier gas has a stronger decomposition effect on the In-rich region. As the duration time of the PPM carrier gas increases, the reduction of In-content in the In-rich region reaches up to 12%, however, only 2% for the In-homogeneous region. These factors lead to the suppression of In-fluctuations.
基金
Project supported by the Science and Technology Major Project of Guangdong Province,China(Grant No.2015B010112001)
the Natural Science Foundation of Guangdong Province,China(Grant No.2015A030312011)
