The effect of gold quantum dots/grating-coupled surface plasmons in inverted organic solar cells.

Kulrisa Kuntamung,Keizo Kato,Kazunari Shinbo,Chutiparn Lertvachirapaiboon,Patrawadee Yaiwong,Akira Baba,Kontad Ounnunkad,Ryousuke Ishikawa

doi:10.1098/rsos.210022

Kulrisa Kuntamung, Keizo Kato + Show 6 more

Open Access

https://doi.org/10.1098/rsos.210022

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Abstract

We studied the effect of gold quantum dots (AuQDs)/grating-coupled surface plasmon resonance (GC-SPR) in inverted organic solar cells (OSCs). AuQDs are located within a GC-SPR evanescent field in inverted OSCs, indicating an interaction between GC-SPR and AuQDs' quantum effects, subsequently giving rise to improvement in the performance of inverted OSCs. The fabricated solar cell device comprises an ITO/TiO2/P3HT : PCBM/PEDOT : PSS : AuQD/silver grating structure. The AuQDs were loaded into a hole transport layer (PEDOT : PSS) of the inverted OSCs to increase absorption in the near-ultraviolet (UV) light region and to emit visible light into the neighbouring photoactive layer, thereby achieving light-harvesting improvement of the device. The grating structures were fabricated on P3HT:PCBM layers using a nanoimprinting technique to induce GC-SPR within the inverted OSCs. The AuQDs incorporated within the strongly enhanced GC-SPR evanescent electric field on metallic nanostructures in the inverted OSCs improved the short-circuit current and the efficiency of photovoltaic devices. In comparison with the reference OSC and OSCs with only green AuQDs or only metallic grating, the developed device indicates enhancement of up to 16% power conversion efficiency. This indicates that our light management approach allows for greater light utilization of the OSCs because of the synergistic effect of G-AuQDs and GC-SPR.

Highlights

The development of high-performance organic thin-film solar cells (OSCs) for harvesting and converting sunlight into electricity has increased rapidly in the past few decades
We found that the best lightharvesting performances of our inverted OSC devices were achieved by incorporating G-AuQDs and an Ag-DVD-R grating, which was obtained from the fluorescent effect of both grating-coupled SPR (GC-SPR) and AuQDs
We studied the effect of incorporating G-AuQDs in the PEDOT : PSS layers on their fluorescence intensity

Summary

Introduction

The development of high-performance organic thin-film solar cells (OSCs) for harvesting and converting sunlight into electricity has increased rapidly in the past few decades. Among the various types of OSCs, inverted OSCs have received significant attention because of their superior device performance and better air stability compared with conventional OSCs [6,7] Their fabrication avoids the use of the acidic PEDOT : PSS on an indium tin oxide (ITO) surface and unstable low-work-function metal electrodes (typically Al or Ca) used in conventional OSC types [6,7]. We demonstrated OSC performance improvement using gold NPs (AuNPs) [17], silver NPs (AgNPs) [18] and metallic nanostructures/gratings [15,18,19,20] These provide better light scattering and trapping and enhance the SPR effect inside the photovoltaic cells, both of which significantly contribute to increasing their light absorption [20]

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