Surface Plasmon‐Assisted Transparent Conductive Electrode for Flexible Perovskite Solar Cells

Abstract

in efficiency and stability with respect to material synthesis, interface modification, and device engineering. [1][2][3][4][5] Moreover, PeSCs hold the great potential as a key element essential in the applications of portable power source and wearable electronics. To bring the imagination to reality for flexible PeSCs, however, is nontrivial, and significant efforts in various aspects should be devoted in terms of low-temperature fabrication compatibility, flexible substrates, and encapsulation. An important aspect is the realization of transparent conductive electrodes (TCEs) with good optical, electrical, and mechanical properties that can replace the conventionally used indium tin oxide (ITO) or fluorine-doped tin oxide (FTO) electrode. The ITO-or FTO-based TCEs feature superior optical transmittance (>90%) and electrical conductivity (<20 Ω sq −1 ), which benefit the realization of flexible PeSCs with a power conversion efficiency (PCE) over 18%. [6] However, these TCEs suffer from the limited mechanical flexibility because of their brittleness. [6][7][8][9][10] To address the aforementioned issue, numerous studies have been dedicated to exploring the potential candidates as a TCE for flexible optoelectronic devices, such as conductive polymer, graphene, and metallic nanostructures. [11][12][13] PCE over 17% has been achieved with the utilization of ITO-free TCEs. [14,15] In particular, metallic nanostructures are regarded as an effective TCE for flexible devices in terms of mechanical flexibility, electrical conductivity, and large-area film uniformity. However, the huge permittivity mismatch between metals and the surrounding media results in a tremendous reflection, which goes against the light transmission purpose. Many solutions have been carried out to suppress the reflection of metal electrodes, including the ultrathin metal films with a thickness less than 20 nm, the use of grid patterns with low coverage, as well as the fabrication of metal nanowire frameworks. [16][17][18][19][20][21][22][23][24] However, the undesirable bump surfaces of TCEs based on metal grids and metal nanowires may introduce additional traps or affect the surface morphology of the subsequently deposited films. [15,21,25,26] These obstacles will thus lead to the unwished charge recombination at the electrode/perovskite interfaces and high leakage current, which further degrade the device performance. Although a flat surface can be achieved for the ultrathin metal film using Flexible perovskite solar cells (PeSCs) possess the extraordinary potential in the applications of portable power sources and wearable electronics because of their superiorities in ease fabrication and efficient power conversion. These features are reinforced when a transparent conductive electrode with good flexibility is achieved. A unique electrode based on Ag periodic mesh (APM) perforated with hexagonal close-packed nanoholes is proposed, showing a square resistance of ≈19.0 Ω sq −1 and optical transmittance of 66.0% in the whole visible region.PeSCs m...

Current advancements on charge selective contact interfacial layers and electrodes in flexible hybrid perovskite photovoltaics

“…However, most of these HTMs were assembled on rigid substrates [121][122][123][124][125][126][127]. Hence in these sub-sections, our discussion will predominantly focus on the HTLs employed in p-i-n structured F-PSCs [24,61,64,85,[128][129][130][131][132][133][134].…”

Flexible transparent electrodes based on metallic micro–nano architectures for perovskite solar cells

“…1 shows the sheet resistance and optical transmittance of different conductive materials recently reported. 10,40,41,52,56,61,[65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82] The FoM value is the factor to evaluate the performance of TEs, which can be calculated using eqn (1): 44,52 FoM ¼ 188:5O R s  TðlÞ À0: 5…”

Hot‐electron emission‐driven energy recycling in transparent plasmonic electrode for organic solar cells

“…17,18 The trapped light in PMEs is lost owing to the dephasing of SPPs and their conversion into heat. 7,8,[19][20][21] Therefore, it is necessary to develop novel strategies for recycling the SPP energy and restraining the nonradiative damping in PMEs for the optimization of OSCs.…”

“…The injected hot-electrons were generally trapped around the PME via nonradiative recombination, and the SPP energy was lost via heat. 19,29 To utilize the injected hot-electrons fully, a hot-electron emission approach was first proposed to recycle the SPP energy trapped in the PMEs for the realization of efficient OSCs. The carrier dynamics of a hot-electron emission in operating OSCs are schematically shown on the right of Figure 1A.…”

“…However, SPPs in bound modes cannot contribute to the optical absorption of the absorber because their exponential decay propagating along the metal surface causes nonradiative damping 17,18 . The trapped light in PMEs is lost owing to the dephasing of SPPs and their conversion into heat 7,8,19–21 . Therefore, it is necessary to develop novel strategies for recycling the SPP energy and restraining the nonradiative damping in PMEs for the optimization of OSCs.…”