Table 2 Light extraction efficiency enhancement and corresponding strategies in recent reports on PeLEDs

2018

(NMA)₂FA_n−1Pb_nI_3n+1 - Polymer

Glass/ITO/MZO/PEIE/PPBH/TFB-PFO/MoOx/Au

Reduced refractive index (1.9) of PPBH; thin emissive layer; LEE: ~25%;

¹⁶

2018

Cs_0.2FA_0.8PbI_2.8Br_0.2

Glass/ITO/Poly-TPD/Perovskite/TPBi/Al

Thin emitting layers; EQE 17.6% (IR)

¹⁶⁸

2018

5-AVA/FAPbI₃

Glass/ITO/ZnO-PEIE/Organic layer/Perovskite/TFB/MoOx/Au

EQE 20.7% (green); light extraction efficiency from 20% to more than 30%

¹⁷

2019

BA: CH₃NH₃PbBr₃ (Br-Pero)

Glass/Epoxy/AAM(TiO₂)/ITO/PEDOT:PSS/Perovskite/F8/Ca/Ag

Nanophotonic substrate (light coupler optical antennas); EQE 17.5% (green); LEE from 10–20% to more than70%;

¹⁹⁹

2019

Modified CsPbBr₃

Glass/ITO/moth-eye ZnO/PEDOT:PSS/Perovskite/TPBi/LiF/Al

Moth-eye ZnO injection layer + half-ball lens; EQE 28.2% (green)

²⁰⁰

2019

MAPbI₃

Glass/NHAs/ITO/Poly-TPD/Perovskite/TPBi/LiF/Al

Nanohole array with high-index contrast; peak EQE 14.6% (red/near IR); 1.64 times light extraction enhancement

²⁰¹

2020

(PEA)₂Cs_n−1Pb_nBr_3n+1

ITO/PVK/Perovskite/TPBi/LiF/Al

Photon recycling; photonic structure control; an out-coupling efficiency of 100% is theoretically possible

¹⁵⁹

2020

MABr modified CsPbBr₃ PNW

Glass/ITO/PEDOT:PSS/Perovskite PNWs/TPBi/Cathode

Perovskite PNWs; EQE 16% (green); LEE from 10–20% to 40−50%

²⁰²

2020

3D, quasi-3D, and quasi-2D

Glass/ITO/UT-PEDOT:PSS/Perovskite/B3PYMPM/LiF/Al

Ultrathin PEDOT:PSS; EQE enhancements 42% 87% 111% for 3D, quasi-3D and quasi-2D, respectively;

¹⁶⁰

2020

(NMA)₂FA_n−1Pb_nI_3n+1

Glass/Au/ZnO/PEIE/MQW-Perovskite/TFB/MoO₃/Au

Microcavity top-emission; the enhanced microcavity effect; EQE 20.2%

²⁹

2021

(PEA/IPA)₂Cs_n−1Pb_nBr_3n+1;

Glass/ITO/NiOx/PVK/Sky-blue Perovskite/TPBi/LiF/Al/Ag/LiF/Red PeNCs

Extract both waveguide and SPP modes

¹⁵⁴