Towards Simplifying the Device Structure of High‐Performance Perovskite Solar Cells

Abstract

Perovskite solar cells (PSCs) are considered one of the most promising nextgeneration examples of high-tech photovoltaic energy converters, as they possess an unprecedented power conversion efficiency with low cost. A typical high-performance PSC generally contains a perovskite active layer sandwiched between an electron-transport layer (ETL) and a hole-transport layer (HTL). The ETL and HTL contribute to the charge extraction in the PSC. However, these additional two layers complicate the manufacturing process and raise the cost. To extend this technology for commercialization, it is highly desired that the structure of PSCs is further simplified without sacrificing their photovoltaic performances. Thus, ETL-free or/and HTL-free PSCs are developed and attract more and more interest. Herein, the commonly used methods in reducing the defect density and optimizing the energy levels in conventional PSCs in order to simplify their structures are summarized. Then, the development of diverse ETL-free or/and HTL-free PSCs is discussed, with the PSCs classified, including their working principles, implemented technologies, remaining challenges, and future perspectives. The aim is to redirect the way toward low-cost and high-performance PSCs with the simplest possible architecture.

Surfactant Sodium Dodecyl Benzene Sulfonate Improves the Efficiency and Stability of Air‐Processed Perovskite Solar Cells with Negligible Hysteresis

“…[ 1–3 ] However, further enhancing the device efficiency toward the theoretical limit is getting harder and harder. [ 4 ] Apart from PCE, the issues of stability and cost are two main barriers for commercialization. [ 5–7 ]…”

Tapered Coaxial Arrays for Photon‐ and Plasmon‐Enhanced Light Harvesting in Perovskite Solar Cells: A Theoretical Investigation Using the Finite Element Method

“…Finally, a conformal plasmonic‐structured Au film with a thickness of T g acts as the anode. As Figure 1 shows, our proposed PSC is hole‐transport‐material (HTM)‐free, which allows for fabricating a simpler and lower‐cost perovskite‐based photovoltaic device [36–41] . Besides, such a HTM‐free PSC is more beneficial for maintaining the arrayed pattern at the Au anode interface.…”

“…As Figure 1 shows, our proposed PSC is hole-transportmaterial (HTM)-free, which allows for fabricating a simpler and lower-cost perovskite-based photovoltaic device. [36][37][38][39][40][41] Besides, such a HTM-free PSC is more beneficial for maintaining the arrayed pattern at the Au anode interface. All simulations about the proposed PSCs were done by FEM.…”

Lead‐Free Halide Double Perovskite Nanocrystals for Light‐Emitting Applications: Strategies for Boosting Efficiency and Stability

“…In recent years, lead halide perovskite nanocrystals, APbX 3 (A = CH 3 NH 3 + (MA + ), NH 2 HCNH 2 + (FA + ), and Cs + , X = Cl, Br, and I) have attracted great interest and been widely used in solar cells, [ 1,2 ] lasers, [ 3,4 ] light‐emitting diodes (LEDs), [ 5,6 ] bioimaging [ 7 ] and photodetectors [ 8,9 ] due to their broad excitation, narrow‐band emission (full width at half‐maximum (FWHM) of 12–42 nm), [ 10,11 ] tunable wavelength (400–700 nm), [ 12‐14 ] high photoluminescence quantum yield ( PLQY ≈ 100%), [ 15,16 ] direct bandgap, [ 17 ] defect tolerance, [ 18 ] long diffusion length, [ 19,20 ] high carrier mobility, [ 21 ] and long carrier lifetime. [ 22,23 ] Especially, lead halide perovskite nanocrystals are suitable for solid‐state lighting and high‐definition display applications due to their wide color gamut ( NTSC ≈ 140%), [ 24,25 ] high color purity, [ 26 ] as well as facile synthesis methods.…”