Optical properties of chain inverted pyramids on silicon
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2020-01-27 |
| Journal | Applied Optics |
| Authors | Quansheng Chen, Yaoping Liu, Hanbo Tang, Yan Wang, Wei Chen |
| Institutions | Songshan Lake Materials Laboratory, Institute of Physics |
| Citations | 2 |
Abstract
Section titled āAbstractāPyramidal structures, including upright pyramids and inverted pyramids (IPs), are commonly used as light-trapping structures for silicon solar cells and silicon photodetectors. In this paper, the possible ray propagation paths in a pyramidal structure are analyzed by establishing a mathematical model in which up to seven ray paths may exist either in a regular or random pyramidal structure. To reduce the reflectivity, the proportion of the quadruple bounce should be increased because of its lower reflectivity. Therefore, a chain IP structure with a quadruple bounce proportion of 10.33% is proposed, of which the overlap value <mml:math xmlns:mml=āhttp://www.w3.org/1998/Math/MathMLā display=āinlineā><mml:mi mathvariant=ānormalā>Ī</mml:mi><mml:mi>x</mml:mi><mml:mrow class=āMJX-TeXAtom-ORDā><mml:mo>/</mml:mo></mml:mrow><mml:mi>w</mml:mi></mml:math> is 0.4. According to theoretical ray-tracing calculations, the weighted average reflectivity is reduced by 0.75% compared to that of a random IP structure. Experimentally, chain IP structures are fabricated from the surface line damage produced by the diamond wire sawing of a silicon wafer as a mask, and the reflectivity of the structures is 0.80% lower than that of a random IP structure. The theoretical analysis and experimental results both show that the chain IP structure has better optical properties than the random IP structure, indicating promising prospects for the abovementioned applications.