| With the advent of plastic fiber-optic communication links in recent years, large-area photodetectors have become very important. Historically, large-area photodetectors have suffered from large capacitances leading to long fall-time transients. MSM photodetectors have very low device capacitances and are well suited for planar integration. However, normal temperature grown GaAs (NTG-GaAs) MSM-PDs have hole-tailing effects in the fall-time transient making them unsuitable for use in communication links. In this thesis, we propose that intermediate temperature grown GaAs (ITG-GaAs) be used as the light absorption layer in a MSM-PD. This gives us the ability to tailor the carier-lifetime to be slightly longer than the transit time, thereby suppressing the hole-tailing effect. The ultra-low device capacitance of the MSM-PD makes practical large-area detectors possible. Finally, with the use of both ITG layers and NTG layers, we can suppress the hole-tailing effect and maintain a high responsivity. This would result in an optimized device structure for large-area applications. |
