The use of plasmonic structures to enhance light trapping in solar cells
has recently been the focus of significant research, but these
structures can be sensitive to various design parameters or require
complicated fabrication processes. Nanosphere lithography can produce
regular arrays of nanoscale features which could enhance absorption of
light into thin films such as those used in novel solar cell designs.
Finite-difference-time-domain simulations are used to model a variety of
structures producible by this technique and compare them against the
use of mirrors as rear reflectors. Through analysis of these
simulations, sensitivity of device performance to parameters has been
investigated. Variables considered include the feature size and array
period, as well as metal and absorber materials selection and thickness.
Improvements in idealized photocurrent density are calculated relative
to the use of rear mirrors that are a standard for solar cells. The
maximum simulated increase to photocurrent density was 3.58mA/cm2
or 21.61% for a 2μm thick Si cell relative to the case where a silver
mirror is used as a rear reflector. From this, an initial set of design
principles for such structures are developed and some avenues for
further investigation are identified.