Broadband and Omnidirectional Antireflection Surfaces Based on Deep Subwavelength Features for Harvesting of the Solar Energy. Issue 12 (19th October 2021)

• Record Type: Journal Article
• Authors: Prajapati, Ashish; Llobet, Jordi; Sousa, Patrícia C; Fonseca, Helder; Calaza, Carlos; Shalev, Gil
• Is Part Of: Solar RRL. Volume 5:Issue 12(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-10-19
• Subjects: angle‐of‐incidence -- broadband omnidirectional anti‐reflection -- light funnels -- light trapping -- nanopillar arrays -- photon management -- solar energy harvesting; Solar energy -- Periodicals; Photovoltaic power generation -- Periodicals; Solar energy -- Research -- Periodicals; Photovoltaic power generation -- Research -- Periodicals; Periodicals; 333.7923
• DOI: 10.1002/solr.202100548
• Languages: English
• ISSNs: 2367-198X

Abstract

Abstract : Broadband and omnidirectional antireflective surfaces are important to various solar energy technologies. The utilization of deep subwavelength features is reported for decrement in the broadband and omnidirectional reflection of the solar spectrum. The study commences with nanopillar (NP) arrays that are well known for their antireflection properties. Deep subwavelength features to the nanopillar arrays are introduced, which yield further decrease in reflection: quasinanolens (qNL), deep subwavelength sidewall scalloping (DSSS), and decreasing the nanopillar bottom diameter to reshape it into a light funnel (LF). Accordingly, surface silicon arrays are realized in a top−down fabrication process: nanopillar arrays, nanopillar arrays incorporated with DSSS, nanopillar arrays incorporated with qNL, nanopillar arrays incorporated with qNL and DSSS, and nanopillar arrays that are transformed into LF arrays and are complemented with qNL and DSSS. It is experimentally shown that utilization of deep subwavelength features produces a broadband reflection decrement with an almost 80% decrement for normal incidence and 60% decrement for an angle of incidence of 80°, for unpolarized illumination. The introduction of deep subwavelength features concludes a 20% decrement in the broadband diffused reflection compared with undecorated NP arrays. The effect of deep subwavelength features is also explored numerically, and the possible underlying light‐trapping mechanisms are discussed. Abstract : Deep subwavelength features are incorporated into nanopillar arrays to yield further decrease in reflection: quasinanolens, deep subwavelength sidewall scalloping, and decreasing nanopillar bottom diameter to reshape it into a light funnel. The incorporation of deep subwavelength features produces broadband reflection decrement of almost 80% decrement for normal incidence and 60% decrement for angle of incidence of 80°, for unpolarized illumination.