The Development of a new Responsivity Prediction Model for In0.53Ga0.47As Interdigitated Lateral p-i-n Photodiode

Abstract

The interdigitated lateral p-i-n photodiode (ILPP) has profound advantages compared to the vertical p-i-n photodiode (VPD) structure mainly due to the ease of fabrication where diffusion or ion implantation can be used to form the p+ and n+ wells in the absorbing layer. A novel ILPP model utilizing In 0.53 Ga 0.47 As (InGaAs) as the absorbing layer was developed and optimized statistically using fractional factorial design (FFD) methodology. Seven model factors were investigated and a new analytical equation was developed to predict the responsivity of ILPP devices as a function of design factors. Comparison between the simulated and calculated responsivity values yielded error ratios of less than 3 %. A statistically optimized ILPP model with -3 dB frequency of 7.5 GHz, responsivity of 0.61 A/W and signal-to-noise ratio (SNR) of 20 dB was developed at an operating voltage of 5 V, wavelength of 1.55 mm and optical input power of 10 Wcm -2 . Hence the model qualifies to be used as a cheap and affordable device in fiber-to-the-home based on passive-optical-networks (FTTH-PON) operating at a minimum speed of 2.5 Gbps.