Enhanced optical properties and dark I-V characteristics of silicon nanowire-carbon quantum dots heterostructures. (August 2023)

• Record Type: Journal Article
• Authors: Mishra, Smruti Medha; Dey, Suman; Singha, Tukai; Mandal, Subhankar; Dehury, Asish K.; Chaudhary, Yatendra S.; Satpati, Biswarup
• Is Part Of: Materials research bulletin. Volume 164(2023)
• Publication Date: 2023-08
• Subjects: Silicon nanowires -- Nitrogen doped carbon quantum dots -- Band gap tuning -- Photoluminescence -- Carrier lifetime; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2023.112262
• Languages: English
• ISSNs: 0025-5408

Abstract

Highlights: Carbon quantum dots (CQD) coated silicon nanowires (SiNW) heterostructures were fabricated via a simple and economically viable approach. Inclusion of nitrogen doped CQDs into the pyramidal SiNW arrays gives enhanced absorption intensity which can act as a good absorber layer in solar cell modules. The optical band gap of the heterostructures shows tunability with the encapsulation of quantum dots layer and such band gap engineering is desirable for solar cell applications. Quantum dots anchoring on the silicon nanowire surface lowers the density of trapped states thus ensuring effective electron transfer across the hetero-interface. The device having pyramidal SiNW and NCQDs has been predicted to give higher power conversion efficiency (PCE) out of the dark I-V curve. Abstract: Herein, we report a silicon nanowire (SiNW) array-carbon quantum dot (CQD) heterostructure photovoltaic device via direct coating of CQD on chemically-etched SiNW arrays aided by Ag. By using carbon quantum dots layer as a competent element for surface passivation and modification for SiNWs, the solar cells efficiency is improved. The 1.6 times absorption enhancement has been recorded for nitrogen doped CQD decorated pyramidal SiNW heterostructure in comparison to that of CQDs coated silicon nanowires on the planar surfaces. Inclusion of nitrogen doped CQDs into the pyramidal SiNW arrays gives enhanced absorption intensity which can act as a good absorber layer in solar cell. The heterostructure also displays a significant photoluminescence in the blue region as probed by using time-resolved photoluminescence (TRPL) technique which provide the insight into the recombination mechanism in the synthesized heterostructures and is discussed in detail. Graphical abstract: Image, graphical abstract