Stoichiometry and Morphology Analysis of Thermally Deposited V2O5−x Thin Films for Si/V2O5−x Heterojunction Solar Cell Applications

• Published in: Materials Vol. 15; no. 15; p. 5243
• Main Authors: Jeong, Gwan Seung, Jung, Yoon-Chae, Park, Na Yeon, Yu, Young-Jin, Lee, Jin Hee, Seo, Jung Hwa, Choi, Jea-Young
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 29.07.2022; MDPI
• Subjects: Aspect ratio; Carrier lifetime; Deposition; Efficiency; Energy; Energy conversion efficiency; Experimentation; heterojunction solar cell; Heterojunctions; Minority carriers; Morphology; Oxygen atoms; passivation; Passivity; Photoelectrons; Photovoltaic cells; Production costs; Silicon wafers; Solar cells; Stoichiometry; Substrates; Temperature effects; Thin films; transition metal oxide; Transition metal oxides; vanadium oxide; Vanadium oxides; Vanadium pentoxide; United States > US
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma15155243

In recent decades, dopant-free Si-based solar cells with a transition metal oxide layer have gained noticeable research interest as promising candidates for next-generation solar cells with both low manufacturing cost and high power conversion efficiency. Here, we report the effect of the substrate temperature for the deposition of vanadium oxide (V2O5−x, 0 ≤ X ≤ 5) thin films (TFs) for enhanced Si surface passivation. The effectiveness of SiOx formation at the Si/V2O5−x interface for Si surface passivation was investigated by comparing the results of minority carrier lifetime measurements, X-ray photoelectron spectroscopy, and atomic force microscopy. We successfully demonstrated that the deposition temperature of V2O5−x has a decisive effect on the surface passivation performance. The results confirmed that the aspect ratio of the V2O5−x islands that are initially deposited is a crucial factor to facilitate the transport of oxygen atoms originating from the V2O5−x being deposited to the Si surface. In addition, the stoichiometry of V2O5−x TFs can be notably altered by substrate temperature during deposition. As a result, experimentation with the fabricated Si/V2O5−x heterojunction solar cells confirmed that the power conversion efficiency is the highest at a V2O5−x deposition temperature of 75 °C.