1：Experimental Design and Method Selection:

The study involves fabricating a thin-film GaAs double junction photodiode using metal-organic chemical vapor deposition (MOCVD), lithographic patterning, and transfer printing. Theoretical models include the Beer-Lambert law for photon distribution and the ABC model for carrier recombination dynamics. Finite-element method simulations (Silvaco, Inc) are used for EQE calculations.

2：Sample Selection and Data Sources:

The device is a microscale GaAs double junction photodiode with specific layer thicknesses and doping concentrations, fabricated and characterized experimentally.

3：List of Experimental Equipment and Materials:

Equipment includes Keithley 2400 source meter for I-V measurements, diode lasers (475 nm and 810 nm), IPCE measurement system (QEX10, PV Measurement), ultrafast pulse laser (Spectra-Physics Mai Tai), single-photon avalanche photodiode detector (TDA 200), time-correlated single photon counting module (TimeHarp 260 PICO Single), and various filters and bias lights. Materials include GaAs epitaxial layers, electrodes (Ge/Ni/Au, Cr/Au), sacrificial layer (Al0.95Ga0.05As), and adhesive for transfer.

4：95Ga05As), and adhesive for transfer. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Fabrication involves MOCVD growth, lithography, metallization, chemical release with HF solution, and transfer printing to substrates. Characterization includes I-V measurements under varied illumination powers and wavelengths, EQE measurements with bias lights, and time-resolved photoluminescence (TRPL) measurements using femtosecond lasers at 410 nm and 800 nm.

5：Data Analysis Methods:

Data analysis employs the ABC model for carrier lifetime fitting, calculations of internal quantum efficiency (η_int) and luminescence coupling efficiency, and comparison with theoretical predictions for photocurrent dependence on power.