Sub-gap defect density characterization of molybdenum oxide

Sub-gap defect density characterization of molybdenum oxide: An annealing study for solar cell applications

Scire, D. (TU Delft Photovoltaic Materials and Devices; Università degli Studi di Palermo)
Procel Moya, P.A. (TU Delft Photovoltaic Materials and Devices)
Gulino, Antonino (University of Catania)
Isabella, O. (TU Delft Photovoltaic Materials and Devices)
Zeman, M. (TU Delft Electrical Sustainable Energy)
Crupi, Isodiana (Università degli Studi di Palermo)

Electrical Sustainable Energy

2020

The application of molybdenum oxide in the photovoltaic field is gaining traction as this material can be deployed in doping-free heterojunction solar cells in the role of hole selective contact. For modeling-based optimization of such contact, knowledge of the molybdenum oxide defect density of states (DOS) is crucial. In this paper, we report a method to extract the defect density through nondestructive optical measures, including the contribution given by small polaron optical transitions. The presence of defects related to oxygen-vacancy and of polaron is supported by the results of our opto-electrical characterizations along with the evaluation of previous observations. As part of the study, molybdenum oxide samples have been evaluated after post-deposition thermal treatments. Quantitative results are in agreement with the result of density functional theory showing the presence of a defect band fixed at 1.1 eV below the conduction band edge of the oxide. Moreover, the distribution of defects is affected by post-deposition treatment. [Figure not available: see fulltext.]

density of states
molybdenum oxide
polaron theory
silicon heterojunction solar cell

http://resolver.tudelft.nl/uuid:c73f2f9a-15ad-4490-9707-688e99c41817

https://doi.org/10.1007/s12274-020-3029-9

1998-0124

Nano Research, 13 (12), 3416-3424

Institutional Repository

journal article

© 2020 D. Scire, P.A. Procel Moya, Antonino Gulino, O. Isabella, M. Zeman, Isodiana Crupi