Fingerprints Indicating Superior Properties of Internal Interfaces in Cu(In,Ga)Se2 Thin-Film Solar Cells

Raghuwanshi M, Chugh M, Sozzi G, Kanevce A, Kühne TD, Mirhosseini H, Wuerz R, Cojocaru-Miredin O (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Advanced Materials Wiley

Book Volume: 34

Article Number: 2203954

Journal Issue: 37

DOI: 10.1002/adma.202203954

Abstract

Growth of Cu(In,Ga)Se2 (CIGS) absorbers under Cu-poor conditions gives rise to incorporation of numerous defects into the bulk, whereas the same absorber grown under Cu-rich conditions leads to a stoichiometric bulk with minimum defects. This suggests that CIGS absorbers grown under Cu-rich conditions are more suitable for solar cell applications. However, the CIGS solar cell devices with record efficiencies have all been fabricated under Cu-poor conditions, despite the expectations. Therefore, in the present work, both Cu-poor and Cu-rich CIGS cells are investigated, and the superior properties of the internal interfaces of the Cu-poor CIGS cells, such as the p–n junction and grain boundaries, which always makes them the record-efficiency devices, are shown. More precisely, by employing a correlative microscopy approach, the typical fingerprints for superior properties of internal interfaces necessary for maintaining a lower recombination activity in the cell is discovered. These are a Cu-depleted and Cd-enriched CIGS absorber surface, near the p–n junction, as well as a negative Cu factor (∆β) and high Na content (>1.5 at%) at the grain boundaries. Thus, this work provides key factors governing the device performance (efficiency), which can be considered in the design of next-generation solar cells.

Involved external institutions

Zentrum für Sonnenenergie- und Wasserstoff-Forschung (ZSW) DE Germany (DE) Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen DE Germany (DE) Universität Paderborn DE Germany (DE) University of Parma / Università degli Studi di Parma IT Italy (IT)

How to cite

APA:

Raghuwanshi, M., Chugh, M., Sozzi, G., Kanevce, A., Kühne, T.D., Mirhosseini, H.,... Cojocaru-Miredin, O. (2022). Fingerprints Indicating Superior Properties of Internal Interfaces in Cu(In,Ga)Se2 Thin-Film Solar Cells. Advanced Materials, 34(37). https://doi.org/10.1002/adma.202203954

MLA:

Raghuwanshi, Mohit, et al. "Fingerprints Indicating Superior Properties of Internal Interfaces in Cu(In,Ga)Se2 Thin-Film Solar Cells." Advanced Materials 34.37 (2022).

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