The performance of polymer/perovskite solar cells (PSCs/PVKSCs) is highly dependent on the interfacial contact between the active layer and electrodes. Water/alcohol soluble interfacial materials, which enable orthogonal processing of high-performance multi-layer PSCs can greatly improve the interfacial contact as well as device performance. Traditional interfacial materials are not compatible with the large-area processing of PSCs using roll-to-roll techniques. Here, we present a series of self-doped interfacial materials with controlled doping properties and high mobility for the interface optimization of PSCs. Self-doped interfacial materials containing n-type conjugated backbone and polar side chains are prepared. It was shown that neutral amino groups undergo photo-induced doping process while the bromide-quaternized groups employ a self-doped mechanism.1 Further study on the counterions of the self-doped interfacial materials shows that the counterions can also induce different self-assembling and doping behavior with different strength, leading to varied charge-transporting properties. 2 More importantly, these self-doped interfacial materials can enable high-performance (>10%) PSCs and still work efficiently in varied thickness, which match well with the requirement of the fabrication of large-area PSCs. Based on the development of self-doped interfacial materials, a high-performance interconnecting layer for tandem solar cells was also developed, which can boost the power conversion efficiency (PCE) of tandem solar cells to 11.35%.3 Moreover, these interfacial materials can passivate the surface traps of perovskite to improve the electron extraction properties of PVKSC, leading to high-performance PVKSCs even when the thickness of interfacial material is more than 200 nm.4 The successful development of self-doped interfacial materials offers a better processing window for potential fabrication of PSCs/PVKSCs using large-area processing method.
1 J. Am. Chem. Soc. 2016, 138, 2004-2013.
2 Mater. Horiz. 2017, 4, 88-97.
3 Adv. Mater. 2016, 28, 4817-4823.
4 Adv. Energy Mater. 2016, 1501534.
2,3,4,5-Tetraarylsiloles are efficient solid-state luminescent materials with good electron-transporting ability. Substitution at the 2,5-positions of silole rings produce various outstanding functional materials that can be used as active layers in organic light-emitting diodes (OLEDs). In this work, two 2,5-dicarbazole-substitued siloles, (2-Cz)2MTPS and (3-Cz)2MTPS, are facilely synthesized and fully characterized. Their thermal, photophysical, electrochemical, and electroluminescent properties are investigated systematically. The results show that these 2,5-dicarbazole-functined siloles are thermally stable and feature aggregation-enhanced emission characteristics with high solid-state photoluminescence efficiencies. Nondoped OLEDs [ITO/N,N'-di(1-naphthyl)-N,N'-diphenyl-benzidine (NPB) (60 nm)/emitter (20 nm)/TPBi (40 nm)/LiF (1 nm)/Al (100 nm)] fabricated by adopting (2-Cz)2MTPS and (3-Cz)2MTPS as light-emitting layers exhibit good performances, with high luminance of 28240 cd m−2 and electroluminescence efficiency of 4.5 cd A−1.
Typically, most low bandgap materials have low absorption with wavelength at around 500 nm.
Besides, the restrictions of active layer thickness of thin film organic solar cells (OSCs) make the
devices reduce to absorb light in long wavelength region (around 700 nm). As absorption would be a
joint effect of material band properties and optical structures, well-designed light-trapping strategies
for these low-bandgap PSCs will be more useful to further enhance efficiencies. We investigate the
change of optical properties and device performances of organic solar cells based on our newly
synthesized low-bandgap material with embedded poly-(3,4-ethylenedioxythiophene):
poly(styrenesulfonate) PEDOT:PSS grating in the photoactive bulk heterojunction
Conference Committee Involvement (3)
Organic, Hybrid, and Perovskite Photovoltaics XX
13 August 2019 | San Diego, California, United States
Organic, Hybrid, and Perovskite Photovoltaics XIX
20 August 2018 | San Diego, California, United States
Organic, Hybrid, and Perovskite Photovoltaics XVIII
6 August 2017 | San Diego, California, United States