Improvement of InGaP solar cells grown with TBP in planetary MOVPE reactor

In this study, the impact of various growth parameters, such as wafer temperature, device structures, and substrate misorientation, on the quality of InGaP epitaxial layers and solar cells grown in a planetary MOVPE reactor using TBP as a P source were investigated and optimized. Results showed that the carrier lifetime in unintentionally n-doped InGaP significantly decreased as the growth temperature increased from 560 to 590 degrees C. At temperatures above 600 degrees C, the growth of InGaP was unsuccessful due to extremely rough surface morphology. The study revealed that InGaP rear homojunction and rear heterojunction solar cells using n-type InGaP base layers displayed improved photo-carrier collection and performance compared to traditional front junction solar cells with p-type InGaP base layers. Notably, InGaP grown on GaAs (001) with a 5 degrees miscut towards (111)A was found to have better quality, while InGaP grown on GaAs (001) with a 6 degrees tilt towards (111)B had worse results in terms of carrier lifetime, PL intensity, and solar cell performance.

Automated summary

In this study, the quality of InGaP epitaxial layers and solar cells grown in a planetary MOVPE reactor using TBP as a P source was investigated and optimized by studying and optimizing various growth parameters, such as wafer temperature, device structures, and substrate misorientation. The carrier lifetime in unintentionally n-doped InGaP decreased significantly with increasing growth temperature, and at temperatures above 600 degrees C, InGaP growth was unsuccessful due to rough surface morphology. Additionally, InGaP rear homojunction and rear heterojunction solar cells using n-type InGaP base layers showed improved performance compared to traditional front junction solar cells with p-type InGaP base layers. The substrate misorientation also affected the quality of InGaP, with better results observed for InGaP grown on GaAs (001) with a 5 degrees miscut towards (111)A and worse results for InGaP grown on GaAs (001) with a 6 degrees tilt towards (111)B in terms of carrier lifetime, PL intensity, and solar cell performance.