High-efficiency (AlGa)As/GaAs solar cells grown by MOVPE using TBAs at low-temperatures and low V/III-ratios

The alternative As-precursor tertiarybutylarsine (TBAs) is used to grow (AlGa)As–GaAs heteroface solar cell structures. In a horizontal reactor (AIX200) a low growth temperature of 625°C and a low V/III-ratio of 10 was used. Solar cell structures using a arsine (AsH3)-based MOVPE process were grown in a multi-wafer reactor (AIX2600G3) using growth temperatures of 700°C and a V/III-ratio of 31. The solar cell efficiencies of both structures are 24.2% (AM 1.5 g). The obtained efficiency values are state of the art and demonstrate that TBAs can be an alternative to the more commonly used arsine with no decrease in the solar cell performance.