1：Experimental Design and Method Selection:

The study involves the fabrication of a co-planar metal-semiconductor-metal nonsymmetrical back to back Schottky diode photodetector using natural superlattice AlGaAs grown by metalorganic vapor phase epitaxy on GaAs (100). The performance of the superlattice based device is compared with that based on high temperature annealed homogeneous AlGaAs.

2：0). The performance of the superlattice based device is compared with that based on high temperature annealed homogeneous AlGaAs. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: Samples were grown on semi-insulating GaAs (100) substrates using Trimethylgallium (TMG) and Trimethylaluminium (TMA) as group III precursors and Arsine (AsH3) as group V source. The growth conditions were kept at a growth rate of ?2 μm/hr, growth temperature of 650 ?C, reactor pressure of 100 mbar, and V/III ratio of

3：List of Experimental Equipment and Materials:

Gold-Germanium alloy (Au88%Ge12%) and Nickel (Ni) were used for the two metal contacts of the MSM structure, deposited by thermal evaporation. Measurements were performed using Keithley 4200 SCS and Tektronix TBS2102 digital storage oscilloscope (DSO). Spectral response was measured using a 450 W Xenon lamp in conjunction with a monochromator (Gemini 180, Horiba Jovin Yvon).

4：Experimental Procedures and Operational Workflow:

The devices were fabricated with the same coplanar junctions on the front face. The current-voltage (i-v) characteristics were analyzed in dark and under illumination conditions with wavelength ranging from 400 to 900 nm. The temporal response was tested under square pulsed light signals in a certain range of frequency.

5：Data Analysis Methods:

The i-v characteristics were analyzed using a three diode model for the superlattice based devices and a double diode model for the homogeneous AlGaAs based device. The variations of the extracted parameters from the electrical equivalent model were discussed in details.