Formation of MoO_x barrier layer under atmospheric based condition to control MoSe₂ formation in CIGS thin film solar cell

ABSTRACT

As part of the device fabrication process, selenization step is required to crystallise the CIGS absorber layer. However, during high temperature selenization process, excessive formation of MoSe₂ can lead to delamination of the film and adverse effect on electrical properties of the solar cells. In this paper, a new method is proposed to form a Molybdenum Oxide (MoO_x) barrier layer in between of the Mo back contact using plasma jet under atmospheric based conditions. The effect of MoO_x compound (MoO₂ and MoO₃) towards the efficiency of the device is investigated. It has been proven that a thin layer of MoO_x barrier layer is able to control the formation of MoSe₂ effectively and provide a significant improvement in electrical properties of the devices. A power conversion efficiency of 5.24% with least efficiency variation across the champion device was achieved which demonstrates the importance of this methodology on small area devices.

KEYWORDS:

• Copper Indium Gallium Selenide
• CIGS thin film solar cells
• MoO_x barrier layer
• atmospheric plasma jet
• MoSe₂

Acknowledgments

This research was under the project entitled “Flexible solar photovoltaics for commercial roof tops and rural communities in Malaysia” which involves collaboration between Loughborough University, UK and Universiti Tenaga Nasional, Malaysia. The authors would like to acknowledge British council Newton Fund (Application ID 216006343) for funding this work.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the British council Newton Fund [216006343];