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Effect of Hydrogen Plasma Treatment on Silicon Quantum Dot Multilayers Using Amorphous SiOx
R. Akaishi, K. Gotoh, S. Kato, N. Usami, Y. Kurokawa
Passivation, Hydrogen, Thin Film Solar Cell, Defect Density, Quantum Dots
New Materials and Concepts for Photovoltaic Devices
Subtopic: New Materials and Concepts for Cells and Modules
Event: 37th European Photovoltaic Solar Energy Conference and Exhibition
Session: 1BV.4.25
83 - 86
ISBN: 3-936338-73-6
Paper DOI: 10.4229/EUPVSEC20202020-1BV.4.25
0,00 EUR
Document(s): paper, poster


The bandgap of silicon quantum dots (Si-QDs) is tunable in a wide range depending on its size, due to the quantum size effect. Si-QD multilayers (Si-QDMLs) are a promising material for a light-absorber of all silicon tandem solar cell, which is possible to overcome the Shockley-Queisser limit. To improve the quality of Si-QDMLs, hydrogen termination to dangling bonds is very important. In this study, we investigated the effects of hydrogen plasma treatment (HPT) on Si-QDMLs. 30-period Si-QDMLs were prepared by plasma-enhanced chemical vapor deposition (PECVD) and an annealing process onto quartz substrates. Raman scattering spectra showed that the hydrogen was introduced into the Si-QDMLs by the HPT. From ESR measurement, the defect density in the Si-QDML was reduced from 1.1×1019 to 8.1×1017 cm-3 by HPT at 600 oC. Conductivity was increased from 3.3×10-8 to 2.9×10-6 S/cm, suggesting that the hydrogen termination to charged defects or the suppression of carrier scattering due to defects. These results clearly showed the HPT is beneficial for reducing defects in the Si-QDMLs and it is possible to improve the film quality of Si-QDMLs.