Fig. 1. Basic principle of optical manipulation of plasma micro/nano-structures in OLEDs and OPVs. (a) Electromagnetic-field distribution of SPP mode at metal/dielectric material interface[36]; (b) decay of SPP mode at metal/dielectric material interface[36]; (c) dispersion relationship of SPP mode and free space photon[36]; (d) SPP dispersion on periodically structured surface (period D)[50]; (e) schematic of plasmonic light scattering in OPVs[55]; (f) schematic of near-filed enhanced effect in OPVs[55

Fig. 2. Laser-assisted holographic lithography. (a) Schematic of holographic lithography based on laser interference[71]; (b) scanning electron microscope (SEM) images of three-dimensional multiscale hierarchical micro/nano-structures[71]

Fig. 3. Nanoimprint lithography. (a) Schematic of thermal NIL[79]; (b) schematic of UV-curable NIL[79]; (c)(d) SEM images of micro/nano-structures fabricated by UV-curable NIL[81-82]; (e) schematic of micro/nano-contact NIL[79]

Fig. 4. Temperature-induced fabrication of micro/nano-structures. (a) Schematic of temperature-induced fabrication of micro/nano-structures[87]; (b) atomic force microscopy (AFM) images of temperature-induced micro-corrugations based on different annealing temperatures (85 ℃ and 105 ℃)[87]; (c) SEM images of temperature-induced complex ordered microstructures based on patterned elastomeric polymer surface[90]

Fig. 5. Light extraction from SPP and waveguide modes in bottom-emitting OLEDs by micro/nano-structures. (a)(b) Angular dependent EL spectra and internal-field simulated distribution of magnetic field intensity in single-period micro/nano-structured OLEDs[104]; (c) extraction of SPP loss at bimetallic electrode interface in OLEDs by dual periodic gratings[111]; (d) schematic of light extraction from transparent OLEDs without metal electrodes[113]

Fig. 6. Light extraction from top-emitting OLEDs. (a) (b) Schematic of cross-coupling of SPP and microcavity modes improving light-extraction efficiency of thick metal electrode and dispersion relation[103]; (c) schematic of TPP-MC hybrid-mode light extraction in white top-emitting OLEDs[140]

Fig. 7. Light trapping in OPVs enhanced by SPP mode. (a) Fabrication process, AFM images of microstructures, and absorption spectra of OPVs based on one-dimensional grating with various of periods[161]; (b) SEM images of periodic micro/nano-structures in OPVs[160]; (c) schematic of light trapping in OPVs enhanced by in-cell and out-cell MEN microstructures and AFM images of MEN microstructures[166]

Fig. 8. Light trapping in OPVs enhanced by Ag NPs with different metal shapes. (a)(b)、(d)(e) TEM images of different Ag NPs[149]; (c) (f) size-distribution histogram of Ag NPs[149]

Fig. 9. Schematic of light trapping in OPVs enhanced by dual plasmonic nanostructures[191]

Fig. 10. Light trapping in OPVs enhanced by composite plasmonic micro/nano-structure. (a) Schematic of composite plasma micro/nano-structure improving light trapping in OPVs[192]; (b) flowchart of fabrication of composite plasmonic micro/nano-structure[192]; (c)-(f) SEM images of composite plasmonic micro/nano-structure (scalebar is 1 μm)[192]