Interface engineering of graphene-silicon Schottky junction solar cells with an Al2O3 interfacial layer grown by atomic layer deposition.

Aaesha Alnuaimi,Irfan Saadat,Ammar Nayfeh,Ibraheem Almansouri

doi:10.1039/c7ra13443f

Aaesha Alnuaimi, Irfan Saadat + Show 2 more

Open Access

https://doi.org/10.1039/c7ra13443f

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Abstract

The recent progress in graphene (Gr)/silicon (Si) Schottky barrier solar cells (SBSC) has shown the potential to produce low cost and high efficiency solar cells. Among the different approaches to improve the performance of Gr/Si SBSC is engineering the interface with an interfacial layer to reduce the high recombination at the graphene (Gr)/silicon (Si) interface and facilitate the transport of photo-generated carriers. Herein, we demonstrate improved performance of Gr/Si SBSC by engineering the interface with an aluminum oxide (Al2O3) layer grown by atomic layer deposition (ALD). With the introduction of an Al2O3 interfacial layer, the Schottky barrier height is increased from 0.843 V to 0.912 V which contributed to an increase in the open circuit voltage from 0.45 V to 0.48 V. The power conversion efficiency improved from 7.2% to 8.7% with the Al2O3 interfacial layer. The stability of the Gr/Al2O3/Si devices was further investigated and the results have shown a stable performance after four weeks of operation. The findings of this work underpin the potential of using an Al2O3 interfacial layer to enhance the performance and stability of Gr/Si SBSC.

Highlights

The high cost and inadequate efficiency of existing solar cell technologies have caused current efforts to focus on investigating new materials to achieve low cost and high efficiency solar cells
Graphene has been utilized in various PV technologies as a transparent electrode, electron and hole transport layer in organic solar cells and catalyst in dye sensitized solar cells (DSSCs).[1,2,3,4,5,6,7,8]
The performance of Gr/ Si Schottky barrier solar cells (SBSC) is highly affected by the high recombination at Gr/Si interface and the continues but non-uniform growth of native oxide that prevents the tunnelling of the photo-generated charge carriers and leading to performance degradation and aResearch and Development Centre, Dubai Electricity and Water Authority (DEWA), Dubai, United Arab Emirates bDepartment of Electrical and Computer Engineering (ECE), Masdar Institute, Khalifa University of Science and Technology, P

Summary

Introduction

The high cost and inadequate efficiency of existing solar cell technologies have caused current efforts to focus on investigating new materials to achieve low cost and high efficiency solar cells. Graphene has been utilized in various PV technologies as a transparent electrode, electron and hole transport layer in organic solar cells and catalyst in dye sensitized solar cells (DSSCs).[1,2,3,4,5,6,7,8] The recent development of Gr/silicon (Si) Schottky barrier solar cells (SBSC) have shown a great potential to produce low cost and high efficiency solar cells with the highest reported efficiency being 15.6%.9,10. Despite the recent efforts in enhancing the electrical and optical performance of Gr/Si SBSC,[9,10,11,12,13,14,15,16,17,18,19,20,21,22,23] further performance optimization is required. The performance of Gr/ Si SBSC is highly affected by the high recombination at Gr/Si interface and the continues but non-uniform growth of native oxide that prevents the tunnelling of the photo-generated charge carriers and leading to performance degradation and

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