Multilayer porous silicon as visible radiation absorber

• Published in: Optical materials Vol. 112; p. 110795
• Main Authors: Fernandes da Silva, Ana Carolina, Berni, Luiz Ângelo
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2021
• Subjects: Black silicon; Eletrochemical etching; Porous silicon; Reflectance; Black silicon; Eletrochemical etching; Porous silicon; Reflectance
• ISSN: 0925-3467
• DOI: 10.1016/j.optmat.2020.110795

Since its accidental discovery in the mid-1950s, porous silicon has attracted great interest due to its wide range of applications. One of them that has been the subject of recent studies is the use of this material as black silicon, in which with the continuous or gradual variation of the refractive index it is possible to significantly reduce the reflectance of silicon surface. In this work, several samples of this material were produced in order to analyze the feasibility of using porous silicon as a radiation absorber in the visible region. The best results obtained were for samples with six layers with refractive index ranging from 1.4 to 2.4, total thickness of 10,800 nm and reflectance of 5%. The influence of porous layer thickness on the reflectance profile was also observed. •Porous silicon has attracted great interest due to its wide range of applications.•Black silicon is obtained with the continuous or gradual variation of the refractive index of porous silicon.•The best results obtained were for samples with reflectance of 5%.