Colloidal Antireflection Coating Improves Graphene–Silicon Solar Cells

TLDR

Carbon nanotube‑Si and graphene‑Si solar cells are attractive for their potential to simplify manufacturing and reduce cost, yet graphene‑Si devices have remained below 10 % efficiency, lagging behind their nanotube‑Si counterparts. The antireflection treatment was realized by a simple spin‑coating process, which significantly increased the short‑circuit current density and the incident photon‑to‑electron conversion efficiency to about 90 % across the visible range. The colloidal antireflection coating raised the monolayer graphene‑Si cell efficiency to 14.5 % under AM1.5 illumination, with a stable effect over time, indicating strong potential for high‑efficiency graphene‑Si solar cells comparable to nanotube‑Si structures.

Abstract

Carbon nanotube-Si and graphene-Si solar cells have attracted much interest recently owing to their potential in simplifying manufacturing process and lowering cost compared to Si cells. Until now, the power conversion efficiency of graphene-Si cells remains under 10% and well below that of the nanotube-Si counterpart. Here, we involved a colloidal antireflection coating onto a monolayer graphene-Si solar cell and enhanced the cell efficiency to 14.5% under standard illumination (air mass 1.5, 100 mW/cm(2)) with a stable antireflection effect over long time. The antireflection treatment was realized by a simple spin-coating process, which significantly increased the short-circuit current density and the incident photon-to-electron conversion efficiency to about 90% across the visible range. Our results demonstrate a great promise in developing high-efficiency graphene-Si solar cells in parallel to the more extensively studied carbon nanotube-Si structures.