151. Bandgap grading and Al0.3Ga0.7As heterojunction emitter for highly efficient GaAs-based solar cells
- Author
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Soo-Hyun Kim, Heon-Min Lee, Sun-Tae Hwang, Hyeunseok Cheun, Byungwoo Park, Hyun Lee, Sangheon Lee, Byung Ho Lee, Taehyun Hwang, and Wonki Yoon
- Subjects
010302 applied physics ,Materials science ,Bandgap grading ,Renewable Energy, Sustainability and the Environment ,business.industry ,Energy conversion efficiency ,Heterojunction ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Band bending ,Coating ,0103 physical sciences ,engineering ,Optoelectronics ,0210 nano-technology ,business ,Layer (electronics) ,Voltage ,Common emitter - Abstract
Both an Al0.3Ga0.7As heterojunction in the p-type emitter and a bandgap-graded layer in the n-type light absorbing base were employed in the GaAs-based solar cells. The simulation by AFORS-HET (Helmholtz-Zentrum Berlin) confirmed that the Al0.3Ga0.7As heterojunction enhanced the open-circuit voltage (Voc) by ~2%, and the n-type bandgap grading increased the fill factor by ~1%, respectively. The increased power conversion efficiency by ~3% supported the simulation results. An additional efficiency gain was obtained by the shape optimization of the band bending in the 80-nm compositional profile, increasing Voc up to 1.103 V. The cell with the anti-reflective coating exhibited high performance with a power conversion efficiency of 28.7% under 1 sun illumination, close to the world record of 28.8%.
- Published
- 2016
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