Development of UV photodetector structures on silicon

• Main Author: Muhammad Osman
• Other Authors: K. Radhakrishnan
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: http://hdl.handle.net/10356/60882
• Institution: Nanyang Technological University

AlxGa1-xN based UV photodetectors on Si samples grown by RF-MBE technique were characterized to study the effects of varying Al % composition on the optical and structural properties of the samples. Photoluminescence (PL), X-Ray Diffraction (XRD), Microscope and Scanning Electron Microscope (SEM) were used to characterize the samples. In addition to that, I – V and Hall Measurement were also done to study the electrical properties of these samples. From the PL data, the Al % composition was determined and it was found that there was an increase in the band gap energy when the Al % composition was increased. A general trend could also be observed for FWHM and TDD against varying Al % composition. However, no obvious trend could be seen on the effects of different Al % composition on the RMS roughness, sheet resistivity and leakage current against Al % composition. After taking into consideration other factors like the Al and Ga flux, it can be seen that the RMS roughness and leakage current increased with increasing Al flux with Ga flux fixed at a constant value. However, the sheet resistivity seemed to decrease with increasing Al flux.