Effects of surface barrier layer in AlGaAs/GaAs solar cells

• Published in: Journal of crystal growth Vol. 425; pp. 330 - 332
• Main Authors: Urabe, Hiroyuki, Kuramoto, Makoto, Nakano, Tomohiro, Kawaharazuka, Atsushi, Makimoto, Toshiki, Horikoshi, Yoshiji
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2015
• Subjects: A3. MBE; A3. Solar cells; Aluminum gallium arsenides; B1. GaAs; Barrier layers; Barriers; Gallium arsenide; Gallium arsenides; Photovoltaic cells; Solar cells; Spectra; Surface barrier; A3. MBE; A3. Solar cells; Surface barrier; B1. GaAs
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2015.02.097

In this paper, we report the effects of surface barrier layers on the characteristics of AlGaAs/GaAs solar cells. The external quantum efficiency (EQE) spectra for AlGaAs barrier samples with different barrier layer AlAs fractions and thickness of the surface barrier layer were measured to increase the solar cell efficiency. The results show that the surface barrier layer is effective to block diffusing photoexcited electrons to the surface while the thicker barrier layer absorbs higher energy photons to generate carriers which recombine at the surface. The optimal surface barrier structure is a 50nm thick Al0.7Ga0.3As. •The EQE value decreases prominently beyond the band gap of the surface barrier layer.•The barrier layer absorbs higher energy photons to generate carriers which would recombine at the surface.•The optimal surface barrier structure is determined to be a 50nm thick Al0.7Ga0.3As.