He Ding

Design rules for net absorption enhancement in pseudo-disordered photonic crystal for thin film solar cells

The role of pseudo-disordered photonic crystals on the absorption efficiency of simplified thin film crystalline silicon solar cells is presented and discussed. The expected short circuit current can thus be further increased compared to a fully optimized square lattice of holes, thanks to carefully controlled positions of the nanoholes in the considered realistic simplified solar cell stack. In addition, the pseudo-disordered structures are less sensitive to the angle of incidence, especially in the long wavelength range.

Nanophotonics for ultrathin crystalline silicon photovoltaics: When photons (actually) meet electrons

Nanopatterning has recently demonstrated to be an efficient method for boosting the light absorption of thin films (< 50 μm) of crystalline silicon. However, convincing solar cell results are still missing. The goal of the European project PhotoNVoltaics is to investigate the impacts that nanopatterns have on thin crystalline silicon solar cells and to identify the conditions for their efficient integration. The present contribution presents the main findings of the consortium so far. Optical modeling and optimization of nanopatterned thin-film c-Si cells have indicated a few trends regarding the design of the optimum pattern for 1-40 μm thin foils: merged inverted nanopyramids, with their progressive profile seem to provide the best combination of antireflective and light trapping properties, together with negligible surface damage and best coating template for subsequent process steps. But despite the high Jsc enhancement that these nanopatterns are expected to bring, and despite the higher efficiency of these nanophotonic structures for 1-2 μm-thin foils, the absolute Jsc values indicate that thicker foils will have to be preferred if direct competition with wafer-based and thin-film technologies is concerned. An ideal structure is taking shape as an IBC heterojunction cell, with a frontside nanopattern and a thickness of 40 μm.

Carefully mixing disorder and periodicity to optimize solar light trapping

Optimum sunlight absorption in thin absorbers such as silicon can be achieved via the introduction of novel pseudo-disordered photonic nanopatterns.

Light trapping in advanced solar cells: photonic crystals and disordered structures

Integrating Photonic Crystals in solar cells is a powerful way to control light absorption. We will present strategies leading to high conversion efficiencies, considering both carrier recombination issues and absorption optimization by complex nanophotonic structures.

Absorption in photonic crystals: from order to disorder

In this communication, we present the potentialities offered by 2D photonic crystals to trap and absorb photons in thin silicon layers. We will specifically focus on the impact of the photonic crystal unit cells symmetry, and the possibility to increase light absorption and generated photocurrent using multi-periodic and pseudo-disordered photonic nanostructures.