The rational design of dopant-free organic hole-transporting layer(HTL) materials is still a challenge for realizing high-efficient and stable p-i-n planar perovskite solar cells(pero-SCs). Here, we synthesized two π...The rational design of dopant-free organic hole-transporting layer(HTL) materials is still a challenge for realizing high-efficient and stable p-i-n planar perovskite solar cells(pero-SCs). Here, we synthesized two π-conjugated small-molecule HTL materials through tailoring the backbone and conjugated side chain to carefully control molecular conformation. The resultant BDT-TPAs Th containing a planar fused benzo[1,2-b:4,5-b′]dithiophene(BDT) core and a conjugated thiophene side chain showed the planar conformation. X-ray crystallography showed a favorable stacking model in solid states under the parallel-displaced π-πand additional S-π weak-bond supramolecular interactions, thus achieving an obviously increased hole mobility without dopants.As an HTL material in p-i-n planar pero-SCs, the marginal solubility of BDT-TPA-s Th enabled inverse diffusion into the perovskite precursor solution for assisting the subsequent perovskite film growth and passivating the uncoordinated Pb2+ ion defects. As a result, the planar p-i-n pero-SCs exhibited a champion power conversion efficiency(PCE) of 20.5% and enhanced moisture stability. Importantly, the BDT-TPA-s Th HTL material also showed weak thickness-photovoltaic dependence, and the pero-SCs with blade-coated BDT-TPA-s Th as a HTL achieved a 15.30% PCE for the 1-cm2 modularized device. This HTL material design strategy is expected to pave the way toward high-performance, dopant-free and printing large-area planar p-i-n pero-SCs.展开更多
基金supported by the National Natural Science Foundation of China (51922074, 51673138, 51820105003)the Tang Scholar, the Priority Academic Program Development of Jiangsu Higher Education Institutions, Collaborative Innovation Center of Suzhou Nano Science and Technology, Collaborative Innovation Center for Newtype Urbanization and Social Governance of Jiangsu Province, National Key Research and Development Program 376 of China (2017YFA0207700)Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX18_2496)。
文摘The rational design of dopant-free organic hole-transporting layer(HTL) materials is still a challenge for realizing high-efficient and stable p-i-n planar perovskite solar cells(pero-SCs). Here, we synthesized two π-conjugated small-molecule HTL materials through tailoring the backbone and conjugated side chain to carefully control molecular conformation. The resultant BDT-TPAs Th containing a planar fused benzo[1,2-b:4,5-b′]dithiophene(BDT) core and a conjugated thiophene side chain showed the planar conformation. X-ray crystallography showed a favorable stacking model in solid states under the parallel-displaced π-πand additional S-π weak-bond supramolecular interactions, thus achieving an obviously increased hole mobility without dopants.As an HTL material in p-i-n planar pero-SCs, the marginal solubility of BDT-TPA-s Th enabled inverse diffusion into the perovskite precursor solution for assisting the subsequent perovskite film growth and passivating the uncoordinated Pb2+ ion defects. As a result, the planar p-i-n pero-SCs exhibited a champion power conversion efficiency(PCE) of 20.5% and enhanced moisture stability. Importantly, the BDT-TPA-s Th HTL material also showed weak thickness-photovoltaic dependence, and the pero-SCs with blade-coated BDT-TPA-s Th as a HTL achieved a 15.30% PCE for the 1-cm2 modularized device. This HTL material design strategy is expected to pave the way toward high-performance, dopant-free and printing large-area planar p-i-n pero-SCs.
