PMMA Thin Film with Embedded Carbon Quantum Dots for Post-Fabrication Improvement of Light Harvesting in Perovskite Solar Cells

Abstract

Perovskite solar cells (PSCs) with a standard sandwich structure suffer from optical transmission losses due to the substrate and its active layers. Developing strategies for compensating for the losses in light harvesting is of significant importance to achieving a further enhancement in device efficiencies. In this work, the down-conversion effect of carbon quantum dots (CQDs) was employed to convert the UV fraction of the incident light into visible light. For this, thin films of poly(methyl methacrylate) with embedded carbon quantum dots (CQD@PMMA) were deposited on the illumination side of PSCs. Analysis of the device performances before and after application of CQD@PMMA photoactive functional film on PSCs revealed that the devices with the coating showed an improved photocurrent and fill factor, resulting in higher device efficiency.

Applications of Carbon Dots in Optoelectronics

“…Poly(methyl methacrylate) (PMMA) was also often used as a matrix for the fabrication of CD-based luminescent films and for fabrication of LEDs and WLEDs [ 9 , 55 ]. In [ 26 ], light-harvesting properties of perovskite solar cells with CDs dispersed in the PMMA layer were improved through the down-conversion effect ( Figure 2 b). In the electroluminescent LED, PMMA can play a role of an isolating layer, which helps to restrain the electron injection from an active CD-containing layer to the hole transport layer, and prevent charge recombination at the anode [ 92 ].…”

“…( b ) Schematics of perovskite solar cells without (left) and with (right) light harvesting PMMA layer with embedded CDs. Reprinted with permission from reference [ 26 ]. ( c ) Photographs (taken under daylight and UV excitation) of green- and red-emissive CDs in solution and those embedded into MTES or APTES matrices to form CD-based glasses for trichromatic white light emitting diodes (WLEDs).…”

“…CDs even found some applications in agriculture, where they were used to improve plant growth and production [ 23 ]. Due to their strong absorption [ 24 ], CDs were used as sensitizers in solar cells [ 25 , 26 ]. Considering a variety of synthetic methods and precursor materials of CDs and their variable degree of crystallization, the electronic structure and optical processes occurring in CDs may undergo significant transformations depending on their inner structure, chemical composition, and types of molecular moieties at their surface [ 2 , 27 ].…”

Perspective on Predominant Metal Oxide Charge Transporting Materials for High-Performance Perovskite Solar Cells

“…In general, five major areas are being investigated to come up with possible solutions for the problems mentioned above. They include (i) perovskite composition and crystal structure (Luo and Daoud, 2016;Mitchell et al, 2017), (ii) engineering of perovskite growth methods (Ng et al, 2015(Ng et al, , 2018Babayigit et al, 2018;Shen et al, 2018;Hu et al, 2020a), (iii) optimization of carrier transport materials and interfaces (Liu et al, 2017;Hu et al, 2020b,c;Wang et al, 2021), (iv) device architectures (Hanmandlu et al, 2018;Ren et al, 2018;Maxim et al, 2020;Shalenov et al, 2020), and (v) encapsulation (Dong et al, 2016;Fu et al, 2019;Emami et al, 2020). Some comprehensive review papers on those topics have also been published (Jiang et al, 2018;Sajid et al, 2018;Ouyang et al, 2019;Hanmandlu et al, 2020;Hu et al, 2020a;Zhou et al, 2020).…”

Photoactive Nanomaterials

“…Three research works [ 1 , 2 , 3 ] reported recent emerging materials, including 2D Bi 2 Se 3 in optoelectronic applications, and discussed fundamental behaviors of dyes in confined media. Another research work reported by Maxim et al [ 4 ] explores the enhancement of light harnessing in perovskite solar cells with embedded carbon quantum dots. Most of the articles are focused on photocatalytic solar fuel generation.…”