Deterministic aperiodic composite lattice-structured silicon thin films for photon management

TL;DR

This paper introduces scalable, deterministic aperiodic nanostructured silicon thin films with tailored photonic lattices that significantly enhance photovoltaic efficiency compared to periodic and unstructured films.

Contribution

It presents a novel scalable nanofabrication method for deterministic aperiodic silicon lattices with functional photonic features, improving solar cell performance.

Findings

Up to +30% short circuit current density over periodic structures

Up to +190% current density compared to unstructured silicon

Successful fabrication of large-area nanostructured silicon films

Abstract

Exotic manipulation of the flow of photons in nanoengineered semiconductor materials with an aperiodic distribution of nanostructures plays a key role in efficiency-enhanced and industrially viable broadband photonic technologies. Through a generic deterministic nanotechnological route, in addition to periodic, transversely quasicrystallographic or disordered random photonic lattices, here we show scalable nanostructured semiconductor thin films on large area nanoimprinted substrates up to 4cm^2 with advanced functional features of aperiodic composite nanophotonic lattices having tailorable supercell tiles. The richer Fourier spectra of the presented artificially nanostructured materials with well-defined lattice point morphologies are designed functionally akin to two-dimensional incommensurate intergrowth aperiodic lattices-comprising periodic photonic crystals and in-plane quasicrystals as subgroups. The composite photonic lattice-structured crystalline silicon thin films with tapered nanoholes or nanocone-nanoholes are presented showing up to +30 % achievable short circuit current density in comparison to a periodic counterpart where as it is up to +190 % in comparison to a reference unstructured silicon thin film of 300 nanometers of thickness. In view of scalable bottom-up integrated device fabrication processes, the structural analysis is further extended to liquid phase crystallized double-side-textured deterministic aperiodic lattice-structured 10 micrometers thick large area crystalline silicon film.