Near-infrared optical absorption enhanced in black silicon via Ag nanoparticle-induced localized surface plasmon.

Peng Zhang,Yadong Jiang,Shibin Li,Zhiming Wu,Xiongbang Wei,Zhi Chen,Chunhua Liu

doi:10.1186/1556-276x-9-519

Abstract

Due to the localized surface plasmon (LSP) effect induced by Ag nanoparticles inside black silicon, the optical absorption of black silicon is enhanced dramatically in near-infrared range (1,100 to 2,500 nm). The black silicon with Ag nanoparticles shows much higher absorption than black silicon fabricated by chemical etching or reactive ion etching over ultraviolet to near-infrared (UV-VIS-NIR, 250 to 2,500 nm). The maximum absorption even increased up to 93.6% in the NIR range (820 to 2,500 nm). The high absorption in NIR range makes LSP-enhanced black silicon a potential material used for NIR-sensitive optoelectronic device.PACS78.67.Bf; 78.30.Fs; 78.40.-q; 42.70.Gi

Highlights

The efficiency of the photovoltaic devices and photoelectronic detectors made from crystalline silicon (C-Si) decreases seriously due to its high reflectivity to the visible and near infrared light
We report a unique, efficient, and easy method to use localized surface plasmon (LSP) to enhance the absorption of black silicon in NIR
The high absorption in NIR range presented in this work is ascribed to the enhancement of LSP induced by nanoparticles embedded into the surface of black silicon

Summary

Background

The efficiency of the photovoltaic devices and photoelectronic detectors made from crystalline silicon (C-Si) decreases seriously due to its high reflectivity to the visible and near infrared light. In order to overcome the intrinsic disadvantage of silicon, many approaches have been explored Most of these methods fall into two categories: 1) anti-reflection coating [1,2] and 2) light-trapping structure, like grating and period structures [3,4,5,6]. Among these methods, a simple and feasible way to obtain high absorption is to blacken the surface of crystalline silicon. As the frequency of incident light matches the frequency of LSP, the light will be absorbed by the metal significantly This phenomenon is called localized surface plasmon resonance (LSPR). Due to the LSP effect, the black silicon with Ag nanoparticles indicates high absorption and low reflectivity in UV-Vis-NIR (250 to 2,500 nm) wavelength

Methods

Results and discussion

Conclusion

24. Younkin RJ

29. Noguez C