A Perylene‐Based Conjugated Polymer Endows Perovskite Solar Cells with 85 °C Durability: The Control of Gas Permeation

Abstract

Organic-inorganic hybrid perovskites in high-efficiency solar cells are prone to degradation at elevated temperatures, especially in the presence of water moisture. A hole-transporting conjugated copolymer (abbreviated as p-NP-E) characteristic of alternating N-annulated perylene and 3,4-ethylenedioxythiophene backbones, to achieve thermostable perovskite solar cells (PSCs) via controlling gas permeation and thus perovskite decomposition is reported. p-NP-E can be conveniently prepared via Pd-catalyzed direct arylation polycondensation. The air-doped p-NP-E composite film containing nonvolatile 4-tert-butylpyridinium bis(trifluoromethanesulfonyl)imide presents a higher hole mobility and an improved conductivity in comparison with the control based on the state-of-the-art polymer, p-TAA, leading to more efficient PSCs. More critically, the p-NP-E based hole transport layer is not only morphologically more heat-resistant, but also features a lower solubility coefficient and diffusion coefficient of both environmental water molecules and gaseous products such as CH 3 I and CH 3 NH 2 from the thermal decomposition of perovskite, enabling the fabrication of 21.7%-efficiency, 85 °C durable solar cells.

Halide Diffusion Equilibrium and Its Impact on Efficiency Evolution of Perovskite Solar Cells

“…[30] The conductivity of the PC 61 BM layer was then measured based on a lateral configuration using interdigital electrodes. [31] Without dopants, the specific conductance (σ) is calculated to be 8.41 × 10 −3 µS cm −1 (Figure 3f). Notably, there are nearly two orders of magnitude enhancement in σ (6.03 × 10 −1 µS cm −1 ) after doping that should substantially benefit the device performance.…”

Various approaches to synthesize water-stable halide PeNCs

“…Commercial products needed a balance between water stability and optoelectronic performance to explore optimal conditions for target applications. It has been demonstrated that adding conductive conjugated polymers 147,148 (such as PEDOT 149 and P3HT 150 ) increases stability, passivates surfaces, and increases intrinsic conductivity. Future research can concentrate on the synthesis of conducting polymer-coated perovskite NCs to enhance the transport characteristics in the films which is rarely explored.…”

The effects of the planarity of the core building block and peripheral donor groups on the photovoltaic performance of triarylated amine-based hole transport materials

“…[27][28][29][30][31] Besides the optimization of the central building block, the peripheral donor groups also play crucial roles in determining the properties and photovoltaic performance of corresponding HTMs. [32][33][34][35][36][37][38][39] However, the effects of the planarity of the core building block together with the peripheral donor groups on the photovoltaic performance of HTMs haven't been compared in detail. Revealing the impact of the planarity of the core building block and peripheral donor groups on the material properties will be favorable for better developing highly efficient HTMs.…”