Surface texturisation for the reduction of light reflection in ZnO/Si heterojunction

ABSTRACT

In this paper, the impact of pyramidal texture on a silicon substrate in ZnO/p-Si heterojunction was investigated. The texturisation of p-type silicon (100) substrate was obtained using the KOH anisotropic wet chemical etching method for different etching times. The RF magnetron sputtering technique was used to deposit ZnO thin films on textured Si substrates and planar Si substrates to form ZnO/Si heterojunction. The surface morphology was studied with field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). Optical properties were investigated using UV-Visible spectroscopy and photoluminescence (PL). The results show that the PL intensity in the visible region of the electromagnetic spectrum increases with the etching time, while a significant reduction is observed in the reflectance. Due to impressive anti-reflection response, ZnO/Si (textured silicon-TS) heterojunction can be effective in improving the efficiency of solar cells.

KEYWORDS:

• Reflection
• KOH texturisation
• RF sputtering
• ZnO
• photoluminescence
• silicon
• antireflection coating

Acknowledgment

The authors are thankful to Late Prof. Vinay Gupta, Department of Physics and Astrophysics University of Delhi, for allowing us to access the lab facility. Author Jyoti Kashyap is thankful to the University Grant Commission (University of Delhi) for providing financial assistance.

Disclosure statement

No potential conflict of interest was reported by the author(s).