Author(s): Wu, ST (Wu, Shaoteng); Chen, QM (Chen, Qimiao); Zhang, L (Zhang, Lin); Ren, HX (Ren, Huixue); Zhou, H (Zhou, Hao); Hu, LX (Hu, Liangxing); Tan, CS (Tan, Chuan Seng)

Source: NANOSCALE DOI: 10.1039/d2nr06493f Early Access Date: FEB 2023

Abstract: Black-Si (b-Si) providing broadband light antireflection has become a versatile substrate for photodetectors, photo-electric catalysis, sensors, and photovoltaic devices. However, the conventional fabrication methods suffer from single morphology, low yield, or frangibility. In this work, we present a high-yield CMOS-compatible technique to produce 6-inch wafer-scale b-Si with diverse random nanostructures. b-Si is achieved by O-2/SF6 plasma-based reactive ion etching (RIE) of the Si wafer which is coated with a GeSn layer. A stable grid of the SnOxFy layer, formed during the initial GeSn etching, acts as a self-assembled hard mask for the formation of subwavelength Si nanostructures. b-Si wafers with diverse surface morphologies, such as the nanopore, nanocone, nanohole, nanohillock, and nanowire were achieved. Furthermore, the responsivity of the b-Si metal-semiconductor-metal (MSM) photodetector in the near-infrared (NIR) wavelength range (1000-1200 nm) is 40-200% higher than that of a planar-Si MSM photodetector with the same level of dark current, which is beneficial for applications in photon detectors, solar cells, and photocatalysis. This work not only demonstrates a new non-lithography method to fabricate wafer-scale b-Si wafers, but may also provide a novel strategy to fabricate other nanostructured surface materials (e.g., Ge or III-V based compounds) with morphology engineering.

Accession Number: WOS:000935184900001

PubMed ID: 36805597

ISSN: 2040-3364

eISSN: 2040-3372

Full Text: https://pubs.rsc.org/en/content/articlelanding/2023/NR/D2NR06493F