Performance Improvement of Polymer Solar Cells by Surface-Energy-Induced Dual Plasmon Resonance

Abstract

The surface plasmon resonance (SPR) effect of metal nanoparticles (MNPs) is effectively applied on polymer solar cells (PSCs) to improve power conversion efficiency (PCE). However, universality of the reported results mainly focused on utilizing single type of MNPs to enhance light absorption only in specific narrow wavelength range. Herein, a surface-energy-induced dual MNP plasmon resonance by thermally evaporating method was presented to achieve the absorption enhancement in wider range. The differences of surface energy between silver (Ag), gold (Au), and tungsten trioxide (WO3) compared by contact angle images enable Ag and Au prefer to respectively aggregate into isolated islands rather than films at the initial stage of the evaporation process, which was clearly demonstrated in the atomic force microscopy (AFM) measurement. The sum of plasmon-enhanced wavelength range induced by both Ag NPs (350-450 nm) and Au NPs (450-600 nm) almost cover the whole absorption spectra of active layers, which compatibly contribute a significant efficiency improvement from 4.57 ± 0.16 to 6.55 ± 0.12% compared to the one without MNPs. Besides, steady state photoluminescence (PL) measurements provide strong evidence that the SPR induced by the Ag-Au NPs increase the intensity of light absorption. Finally, ultraviolet photoelectron spectroscopy (UPS) reveals that doping Au and Ag causes upper shift of both the work function and valence band of WO3, which is directly related to hole collection ability. We believe the surface-energy-induced dual plasmon resonance enhancement by simple thermally evaporating technique might pave the way toward higher-efficiency PSCs.

Efficiency Improvement of MAPbI3 Perovskite Solar Cells Based on a CsPbBr3 Quantum Dot/Au Nanoparticle Composite Plasmonic Light-Harvesting Layer

“…Noble metal (gold and silver) nanoparticles have proven to be an effective route to increase the light-harvesting capability in solar cells due to their localized surface plasmon resonance effects (LSPR). By adjusting the shape and size of the metal nanoparticles, the characteristic wavelength of the plasmon effect can be changed [28][29][30], thereby improving light absorption, carrier generation, and power conversion efficiency; this has been successfully used to improve the PCEs of solar cells [31][32][33][34][35][36].…”

Recent Advances of Plasmonic Organic Solar Cells: Photophysical Investigations

“…On the other hand, metallic NPs have been doped in HTL such as PEDOT:PSS, WO 3 , or MoO 3 [54]. For instance, dual Au-Ag NPs in the WO 3 HTL extended the wavelength range of light absorption due to the backward scattering and LSPR effect.…”

Light Manipulation in Organic Photovoltaics

“…Taking into account the limited spectral range response with single type of metal NPs, dual metal NPs (i.e., Au and Ag NPs) were presented near the rear electrode of OPVs for SPR-induced absorption enhancement in almost entire absorption range of the photoactive layer by both Ag NPs (350−450 nm) and Au NPs (450−600 nm), leading to a signifi cant improvement of ≈43% in PCE. [ 177 ] Recently, high-effi ciency OPVs were achieved via the incorporation of plasmonic metal NPs into both HEL and EEL to Reproduced with permission. [ 186 ] Copyright 2013, Nature Publishing Group.…”

“…The corresponding OPVs with an optimized 8 nm‐thick Au shown a dramatically increased PCE from ≈4.67% to ≈6.63% due to the plasmonic backscattering effect and modified electrical characteristics. Taking into account the limited spectral range response with single type of metal NPs, dual metal NPs (i.e., Au and Ag NPs) were presented near the rear electrode of OPVs for SPR‐induced absorption enhancement in almost entire absorption range of the photoactive layer by both Ag NPs (350−450 nm) and Au NPs (450−600 nm), leading to a significant improvement of ≈43% in PCE …”