Cross-sectional transmission electron microscopy and high-resolution electron microscopy were used to investigate micro-twins in GaP/(AlxGa1–x)0.52In0.48P/GaAs double heterostructure light-emitting diodes. There was a difference between micro-twins which extended from the GaP/(AlxGa1–x)0.52In0.48P interface into the GaP layer, and micro-twins which existed in the GaP layer. High-resolution electron microscopic measurements showed that the lengths of micro-twins extending from the GaP/AlGaInP interface, along <112> directions, were proportional to their thickness. The micro-twins in the GaP layer did not obey that relationship. It was not apparent that those micro-twins which extended from the interface contained more than 7 atom layers. A formation mechanism was proposed for the micro-twins which extended from the interface, and calculations were performed. The theoretical results were found to be in agreement with the experimental measurements.

Microtwin Formation Mechanism in GaP/AlGaInP/GaAs Double Heterostructure Light-Emitting Diodes. W.Zeng, Y.S.Li, G.Ji, N.Y.Huang, J.J.Wang, X.F.Zong: Journal of Vacuum Science and Technology B, 2001, 19[2], 502-5