Additive‐Free Transparent Triarylamine‐Based Polymeric Hole‐Transport Materials for Stable Perovskite Solar Cells

Abstract

Triarylamine-based polymers with different functional groups were synthetized as hole-transport materials (HTMs) for perovskite solar cells (PSCs). The novel materials enabled efficient PSCs without the use of chemical doping (or additives) to enhance charge transport. Devices employing poly(triarylamine) with methylphenylethenyl functional groups (V873) showed a power conversion efficiency of 12.3 %, whereas widely used additive-free poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) demonstrated 10.8 %. Notably, devices with V873 enabled stable PSCs under 1 sun illumination at maximum power point tracking for approximately 40 h at room temperature, and in the dark under elevated temperature (85 °C) for more than 140 h. This is in stark contrast to additive-containing devices, which degrade significantly within the same time frame. The results present remarkable progress towards stable PSC under real working conditions and industrial stress tests.

Non‐Conjugated Polymer as an Efficient Dopant‐Free Hole‐Transporting Material for Perovskite Solar Cells

“…Additionally, D–A conjugated polymer dopant‐free HTMs with rigid conjugated backbones are usually difficult to process into good thin films owing to solubility problems. More recently, PTAA derivatives and poly(3,4‐ethylenedioxythiophene) have been developed as efficient dopant‐free polymer HTMs . However, cost‐effective dopant‐free HTMs for PSCs with PCEs up to 16 % remain rare.…”

Perovskite Solar Cells: From the Laboratory to the Assembly Line

“…Matsui et al. reported on an additive‐free polymer, V873, reaching 13 % PCE and promising stability at elevated temperatures . Kim et al.…”

Hole Transport Materials in Conventional Structural (n–i–p) Perovskite Solar Cells: From Past to the Future

“…The well‐known polymer, polytriarylamine (PTAA), is a polymer version of a small molecular TPA‐based material. A few groups have developed PTAA derivatives by controlling functional groups or connecting it with other π‐linkers . In 2016, a device employing PTAA with methylphenylethenyl groups ( V873 ) exhibited 12.29% of efficiency without dopants ( Figure 5 ).…”

“…In 2016, a device employing PTAA with methylphenylethenyl groups ( V873 ) exhibited 12.29% of efficiency without dopants ( Figure 5 ). As another concept, some groups reported side‐chain polymers, including non‐conjugated polyvinyl main chains with hole transport side‐chains . They generally have properties of good electron‐blocking capacity and excellent film formability.…”