Abstract
Optimization and design of silicon solar cells by exploiting light scattering frommetal nanoparticles to increase
the efficiency is addressed in the small particle limit from a fundamental point of view via the dyadic Green’s
function formulation. Based on the dyadic Green’s function (Green’s tensor) of a three-layer geometry, light
scattering from electric point dipoles (representing small metal scatterers) located within a thin layer sandwiched
between a substrate and a superstrate is analyzed. Starting from the full dyadic Green’s function we derive
analytical near- and far-field approximations. The far-field approximations enable efficient, exact, and separate
evaluation of light scattering into waves that propagate in the substrate or the superstrate. Based on the near-field
approximation we present a semianalytical expression for the total near-field absorption in the substrate. The
theoretical approach is used to analyze realistic configurations for plasmon-assisted silicon solar cells. We show
that by embedding metal nanoscatterers in a thin film with a high refractive index (rutile TiO2 with n ≈ 2.5) on
top of the silicon, the fraction of scattered light that couples into the solar cell can become larger than 96%, and
an optical path length enhancement of more than 100 can be achieved.
the efficiency is addressed in the small particle limit from a fundamental point of view via the dyadic Green’s
function formulation. Based on the dyadic Green’s function (Green’s tensor) of a three-layer geometry, light
scattering from electric point dipoles (representing small metal scatterers) located within a thin layer sandwiched
between a substrate and a superstrate is analyzed. Starting from the full dyadic Green’s function we derive
analytical near- and far-field approximations. The far-field approximations enable efficient, exact, and separate
evaluation of light scattering into waves that propagate in the substrate or the superstrate. Based on the near-field
approximation we present a semianalytical expression for the total near-field absorption in the substrate. The
theoretical approach is used to analyze realistic configurations for plasmon-assisted silicon solar cells. We show
that by embedding metal nanoscatterers in a thin film with a high refractive index (rutile TiO2 with n ≈ 2.5) on
top of the silicon, the fraction of scattered light that couples into the solar cell can become larger than 96%, and
an optical path length enhancement of more than 100 can be achieved.
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Physical Review B |
| Vol/bind | 83 |
| Nummer | 085419 |
| ISSN | 2469-9950 |
| DOI | |
| Status | Udgivet - 23 feb. 2011 |