Germanium-on-Glass solar cells: fabrication and characterization

• DOI: 10.1364/ome.3.000216
• Publication Date: 2013-01-10T21:07:32Z
• Authors: Vito Sorianello; Lorenzo Colace; Carlo Maragliano; Dominic Fulgoni; Lee Nash; Gaetano Assanto
• Keywords: photovoltaics; germanium; wafer bonding; 0103 physical sciences; Energy Research; 01 natural sciences; 7. Clean energy; Electronic, Optical and Magnetic Materials

We report on Germanium on Glass solar cells realized by wafer bonding, layer splitting and epitaxial regrowth. We provide a detailed description of the layer transfer process and discuss the material characterization. The solar cells are fabricated and tested to extract the most significant figures of merit, evaluating their performance versus device area and operating temperature. The cells exhibit typical conversion efficiencies exceeding 2.4% under AM1.5 irradiation and a maximum efficiency of 3.7% under concentrated excitation. This Germanium on Glass approach is promising in terms of added flexibility in multi-junction engineering and allows a significant cost reduction thanks to the re-usability of the Ge substrates.