Broadband infrared absorption enhancement by electroless-deposited silver nanoparticles

Nanophotonics

article

Claudia Gritti¹  Søren Raza²  Shima Kadkhodazadeh³  Beata Kardynal⁴  Radu Malureanu¹  N. Asger Mortensen¹  Andrei V. Lavrinenko¹ 

[1] Department of Photonics Engineering, Technical University of Denmark;Centre for Nano Optics, University of Southern Denmark, Campusvej 55;Center for Electron Nanoscopy (CEN), Technical University of Denmark;Peter Grünberg Institute (PGI-9), Research Centre Jülich;Center for Nanostructured Graphene (CNG), Technical University of Denmark

关键词: plasmonic nanoparticles;    absorption enhancement;    random nanoparticles;    electroless plating;    electron energy loss spectroscopy;   

DOI  :  10.1515/nanoph-2016-0114

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Decorating semiconductor surfaces with plasmonic nanoparticles (NPs) is considered a viable solution for enhancing the absorptive properties of photovoltaic and photodetecting devices. We propose to deposit silver NPs on top of a semiconductor wafer by a cheap and fast electroless plating technique. Optical characterization confirms that the random array of electroless-deposited NPs improves absorption by up to 20% in a broadband of near-infrared frequencies from the bandgap edge to 2000 nm. Due to the small filling fraction of particles, the reflection in the visible range is practically unchanged, which points to the possible applications of such deposition method for harvesting photons in nanophotonics and photovoltaics. The broadband absorption is a consequence of the resonant behavior of particles with different shapes and sizes, which strongly localize the incident light at the interface of a high-index semiconductor substrate. Our hypothesis is substantiated by examining the plasmonic response of the electroless-deposited NPs using both electron energy loss spectroscopy and numerical calculations.

【 授权许可】

CC BY