Zinc Porphyrin–Ethynylaniline Conjugates as Novel Hole-Transporting Materials for Perovskite Solar Cells with Power Conversion Efficiency of 16.6%

Abstract

New zinc porphyrins Y2 and Y2A2 have been utilized in perovskite solar cells specifically as hole-transporting materials (HTMs) rather than photosensitizers. The combination of MAPbI3 as photosensitizer and porphyrins as HTMs is a potential alternative to well-known MAPbI3/Spiro-OMeTAD hybrids owing to high performance and versatility toward molecular engineering of porphyrin families. A high efficiency of 16.60% is achieved by n-butyl tethered Y2 HTM (V OC = 0.99 V; J SC = 22.82 mA cm–2) which is comparable to that of Spiro-OMeTAD of 18.03% (V OC = 1.06 V; J SC = 22.79 mA cm–2). Both materials possess similar highest occupied molecular orbital level and the same order of magnitude of hole mobility at 10–4 cm2 V–1 s–1. The slightly poorer performance of 10.55% (V OC = 1.01 V; J SC = 17.80 mA cm–2) is obtained for n-dodecyl tethered Y2A2 HTM. This is believed to stem from more surface pinholes when deposited on perovskite leading to an order of magnitude slower mobility.

Advances in hole transport materials engineering for stable and efficient perovskite solar cells

“…In pursuit of cost effective and dopant free HTM materials, various research groups reported alternative small molecule based HTMs (listed in Table 4) which not only improved the PV parameters but also the stability of PSCs. Small molecules based HTMs can be mainly classified as: pyrenes derivatives [120], thiophenes derivatives [121], triazine derivatives [122] and porphyrins derivatives [123]. 4.1.3.1.…”

“…Zinc porphyrin dyes have demonstrated remarkable PV performance in dye sensitized solar cells [128,129], and recently, as a potential alternative HTM to well known Spiro-OMeTAD in PSCs. Hsien Hsin et al [123] designed zinc porphyrin HTMs, namely, Y 2 (Full name not available) and Y 2 A 2 (Full name not available). A high PCE~16.6% is achieved by Y 2 HTM which is comparable to that of Spiro-OMeTAD of~18.03%.…”

Metallated Macrocyclic Derivatives as a Hole – Transporting Materials for Perovskite Solar Cells

“…Recently, metallated porphyrin dyes used as a sensitizer for dye‐sensitized solar cells have achieved a power conversion efficiency of 13 % . Yu and his group introduced A 2 B 2 metallated porphyrin as a potential alternative HTMs, namely Y2 and Y2A2, to well‐known spiro‐OMeTAD in PSCs (Figure ) . Y2 based solar cells exhibited high performance (∼16.6 %) which is comparable to that of spiro‐OMeTAD of ∼18.03 % (Figure ).…”

“…These materials have good thermal stability (384 °C) compared to the spiro‐OMeTAD. Y2 based solar cells have good stability and high reproducibility with consistent efficiencies . Similarly, zinc(II) 5,10,15,20‐tetrakis[5‐(p‐acetylthiopentyloxy) phenyl] porphyrin was employed as a buffer layer between PEDOT: PSS and perovskite films in inverted planar PSCs to modify the interfacial properties.…”

Development of electron and hole selective contact materials for perovskite solar cells

“…The first report from Li et al showed zinc chlorophyll aggregates as efficient biocompatible dopant-free HSM for perovskite solar cells with a PCE of 11.44% [60]. Then Chou et al reported the best-performing porphyrin based solar cell with symmetric ethynylanilinesubstituted porphyrins (29) as HSM giving a PCE of 16.60% [46].…”