Effects of rapid thermal annealing on the optical properties of strain-free quantum ring solar cells
1 State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China
2 Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR, 72701, USA
3 College of Electronics and Information, Kwangwoon University, Nowon-gu, Seoul, 139-701, South Korea
Nanoscale Research Letters 2013, 8:5 doi:10.1186/1556-276X-8-5Published: 2 January 2013
Strain-free GaAs/Al0.33Ga0.67As quantum rings are fabricated by droplet epitaxy. Both photoresponse and photoluminescence spectra confirm optical transitions in quantum rings, suggesting that droplet epitaxial nanomaterials are applicable to intermediate band solar cells. The effects of post-growth annealing on the quantum ring solar cells are investigated, and the optical properties of the solar cells with and without thermal treatment are characterized by photoluminescence technique. Rapid thermal annealing treatment has resulted in the significant improvement of material quality, which can be served as a standard process for quantum structure solar cells grown by droplet epitaxy.