研究目的
Investigating the feasibility of metalorganic vapor phase epitaxy (MOVPE) for extremely rapid growth of GaAs for solar cell applications, focusing on increasing growth rates up to 120 μm/h, reducing V/III ratios to lower material costs, and evaluating crystalline quality and photovoltaic performance.
研究成果
High-speed MOVPE growth of GaAs up to 120 μm/h is feasible with comparable quality to conventional methods. Reducing V/III ratios can increase growth rates and lower material costs, but very low ratios (e.g., 5) may degrade performance due to carbon incorporation. The reactor design enables significant cost reduction for III-V photovoltaic production, with potential for further improvements in throughput and efficiency.
研究不足
Surface morphology deteriorates at high growth rates due to insufficient adatom migration. Carbon incorporation increases at low V/III ratios, potentially degrading solar cell performance. The maximum growth rate is limited by the mass flow controller capacity. Back-diffusion issues in the reactor could cause contamination, affecting quality.
1：Experimental Design and Method Selection:
Used a horizontal MOVPE reactor designed for high growth rates, based on previous research. Employed trimethylgallium (TMGa), trimethylindium (TMIn), trimethylaluminium (TMAl), arsine (AsH3), phosphine (PH3), disilane (Si2H6), and diethylzinc (DEZ) as source materials. GaAs substrates with specific orientations were used. Growth rates were varied by adjusting TMGa supply and V/III ratios.
2：Sample Selection and Data Sources:
2-inch diameter GaAs substrates oriented (100) ± 0.5° with 2° misorientation towards [110]. Samples included non-doped GaAs and doped layers for solar cells.
3：5° with 2° misorientation towards [110]. Samples included non-doped GaAs and doped layers for solar cells.
List of Experimental Equipment and Materials:
3. List of Experimental Equipment and Materials: Horizontal MOVPE reactor (Taiyo Nippon Sanso, HR3335), mass flow controllers, TMGa, TMIn, TMAl, AsH3, PH3, Si2H6, DEZ, GaAs substrates, scanning electron microscopy (SEM), atomic force microscopy (AFM), photoluminescence (PL) setup with 405 nm InGaN laser diode, electrochemical capacitance–voltage (ECV) profiler, secondary ion mass spectroscopy (SIMS), photolithography mask, AuGe/Ni and Ag/Au metals for contacts.
4：Experimental Procedures and Operational Workflow:
GaAs layers were grown at various rates (up to 120 μm/h) and V/III ratios (5 to 40). Thickness measured via SEM cross-sections, surface roughness via AFM, crystalline quality via low-temperature PL, carrier concentrations via ECV, carbon concentration via SIMS. Solar cells fabricated with specific layer structures, and I-V characteristics and EQE measured under AM1.5G illumination.
5：0). Thickness measured via SEM cross-sections, surface roughness via AFM, crystalline quality via low-temperature PL, carrier concentrations via ECV, carbon concentration via SIMS. Solar cells fabricated with specific layer structures, and I-V characteristics and EQE measured under AM5G illumination.
Data Analysis Methods:
5. Data Analysis Methods: Statistical comparison of thickness uniformity, carrier concentration, PL spectra intensities, and solar cell performance parameters (Jsc, Voc, FF, efficiency).
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
