Extended Near‐Infrared Photovoltaic Responses of Perovskite Solar Cells by p‐Type Phthalocyanine Derivative

Abstract

The absent photo‐response in near‐infrared (NIR) light (>800 nm) of lead‐based perovskite solar cells (PSCs) limits the further improvement of their power conversion efficiency (PCE). Here, a narrow bandgap p‐type phthalocyanine derivative (Copper(II) 2,3,9,10,16,17,23,24‐octakis((4‐(bis(4‐methoxyphenyl)amino)phenyl)ethynyl)phthalocyanine –8TPAEPC) with NIR absorption is synthesized to extend the photovoltaic response of perovskite to 850 nm. After doping the 8TPAEPC into the perovskite photoactive layer, the perovskite crystal quality is improved, resulting in its good electrical conductivity and less surface defects. Furthermore, the molecules stacking on the grain boundaries construct the charge transportation paths, as well as the p–n bulk heterojunction with enhanced built‐in potential. The target PSCs are optimized with notably enhanced PCE from 20% up to 22.10%, and excellent stability that is over 80% of the initial level at 70–80% relative humidity can be maintained for more than 500 h, benefiting from the improved hydrophobicity of 8TPAEPC. In addition, 8TPAEPC also serves as a dopant‐free, highly carrier‐mobile, and moreover, NIR‐responsive hole transport layer (HTL) with boosted PCE of 20.42% that reaches state of the art level among the dopant‐free metal phthalocyanines HTL‐based PSCs.

Phthalocyanine in perovskite solar cells: a review

“…The photovoltaic properties of some selected perovskite devices using Pc compounds as additives in the perovskite layer are summarized in Table 4. 139–147…”

“…8TPAEPC ( 74 ), a CuPc compound with eight triphenylamine groups grafted into the peripheral side of Pc, was used as the dopant for a mixed-ion perovskite film and enhanced the PCE of the perovskite devices from 20% to 22.10%. 147 As a narrow band gap additive, 8TPAEPC could extend the NIR photo-response of the perovskite film from 760 to 850 nm, which consequently enhanced the J SC value of the device from 22.8 to 24 mA cm −2 . It was indicated that there are electrostatic interactions between 8TPAEPC and perovskite molecules, which assisted the crystal growth of the perovskite, leading to more packed crystal grains and smoother surface in the final film.…”

“…The photovoltaic properties of some selected perovskite devices using Pc compounds as additives in the perovskite layer are summarized in Table 4. [139][140][141][142][143][144][145][146][147] Tang and coworkers explored the impact of post-treating the MAPbI 3 perovskite layer using tetra-ammonium-substituted ZnPc on the device performance. 144 The two-dimensional (ZnPc) 0.5 MA nÀ1 Pb n I 3n+1 was constructed in the grain boundaries of the MAPbI 3 film by immersing the as-fabricated perovskite layer in an isopropanol solution of the ZnPc derivative (71), resulting in the successful passivation of defects and reduced trap-assisted recombination.…”

Phthalocyanines, porphyrins and other porphyrinoids as components of perovskite solar cells

“…8TPAEPC was also applied as dopant-free HTM yielding 20.42% PCE and showing that also provides good moisture stability. 74…”

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.…”