Reactive-ion-etched glass surface with 2D periodic surface texture for application in solar cells

Abstract

Thin-film silicon solar cells are promising candidates for the low-cost production of electricity from sunlight. However, their efficiency remains relatively low, which is one of the major issues for their commercialisation. In the thin-film silicon technology, light trapping is an important design consideration for achieving a higher device efficiency. An advanced light-trapping technology is expected to boost the efficiency of solar cells further. Therefore, we investigated the development of an advanced light-trapping scheme in a two-dimensional periodic surface structure produced via inductively coupled plasma reactive-ion etching. The texture of the glass surface was varied under various plasma conditions. For the various shapes and sizes of the obtained surface texture, the increased height and base angle of the individual texture showed an overall increase in the diffused transmission of light. In some cases, the diffused transmission was as high as 89 % of the total light transmitted through the glass. The effect of the textured glass on a solar cell was investigated through simulation. Results show that the efficiency of a single-junction solar cell can be enhanced significantly when such a textured glass is used instead of a non-textured glass.