Wide bandgap nitride semiconductors have recently attracted a great level of attention owing to their direct bandgaps in the visible to ultraviolet regions of the spectrum. A number of scientific challenges remain, however, including important issues such as the determination and control of film polarity and relative extent of various polarization effects. Polarization effects arise from two sources: 1) spontaneous polarization at heterointerfaces due to the ionic wurtzite nitride bonds, and 2) strain-induced piezoelectric polarization caused by lattice misfit or thermal strain. Polarization effects can impact heterojunction structures such as MODFETs and quantum wells. In quantum wells, the fundamental electron-heavy-hole transition in GaN/AlGaN quantum wells is observed to red-shift well below the GaN bulk gap for well widths larger than 3 nm for the specific quantum wells investigated. Polarization effects as pertained to nitride semiconductor heterostructures and devices will be treated.
|Journal||Journal of the Korean Physical Society|
|Issue number||SUPPL. 3|
|State||Published - 1999|