M ‐plane GaN‐based dichroic photodetectors

The in-plane asymmetry of M -plane GaN films was used to fabricate polarization-sensitive photodetectors. The measured contrasts between the detected light polarized perpendicular and parallel to the c-axis are as high as 7.25 at 363 nm for a 0.4 μm thick film. For other film thicknesses, the polarization-sensitive bandwidth can be increased. At the same time, the position of the maximum contrast is also affected by the film thickness through a different strain state. Considerations for the detector design show that the film thickness affects both, the contrast and polarization-sensitive bandwidth, through the absorption and the effect of the strain on the valence-band splitting. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)