TY - JOUR
T1 - A pure and stable intermediate phase is key to growing aligned and vertically monolithic perovskite crystals for efficient PIN planar perovskite solar cells with high processibility and stability
AU - Bai, Yang
AU - Xiao, Shuang
AU - Hu, Chen
AU - Zhang, Teng
AU - Meng, Xiangyue
AU - Li, Qiang
AU - Yang, Yinglong
AU - Wong, Kam Sing
AU - Chen, Haining
AU - Yang, Shihe
N1 - Publisher Copyright:
© 2017 Elsevier Ltd
PY - 2017/4/1
Y1 - 2017/4/1
N2 - Solvent engineering has been extensively used to control the growth of a high-quality perovskite layer for solar cells by forming intermediate phases. However, the intermediate phase formation is often poorly understood and its effects on the perovskite layer growth are still elusive. Here, we have conducted a systematic and in-depth study on the above two issues through a strict control over the DMSO/DMF ratio in CH3NH3PbI3 perovskite solutions, and thus an effective control over the compositions of intermediate films. The films thus obtained, including perovskite, perovskite/MA2Pb3I8(DMSO)2 and MA2Pb3I8(DMSO)2, afford perovskite crystals via down-growth, down-and up-growth, and up-growth mechanisms, respectively. Significantly, the up-growth perovskite crystals from the pure MA2Pb3I8(DMSO)2 exhibits the best interface contact with NiO substrate, optimal alignment without horizontal grain boundaries and a relatively large grain size, which facilitate charge transfer and reduce charge recombination in PSCs. As a result, the PIN planar PSCs based on NiO have achieved a PCE of 18.4%, a value which is among the highest for NiO-based PSCs, with the highest stability among the tested sample cells. Furthermore, the pure MA2Pb3I8(DMSO)2 intermediate phase presents a high long-term stability, which enlarges the operating window for perovskite deposition and thus considerably improves the device processibility.
AB - Solvent engineering has been extensively used to control the growth of a high-quality perovskite layer for solar cells by forming intermediate phases. However, the intermediate phase formation is often poorly understood and its effects on the perovskite layer growth are still elusive. Here, we have conducted a systematic and in-depth study on the above two issues through a strict control over the DMSO/DMF ratio in CH3NH3PbI3 perovskite solutions, and thus an effective control over the compositions of intermediate films. The films thus obtained, including perovskite, perovskite/MA2Pb3I8(DMSO)2 and MA2Pb3I8(DMSO)2, afford perovskite crystals via down-growth, down-and up-growth, and up-growth mechanisms, respectively. Significantly, the up-growth perovskite crystals from the pure MA2Pb3I8(DMSO)2 exhibits the best interface contact with NiO substrate, optimal alignment without horizontal grain boundaries and a relatively large grain size, which facilitate charge transfer and reduce charge recombination in PSCs. As a result, the PIN planar PSCs based on NiO have achieved a PCE of 18.4%, a value which is among the highest for NiO-based PSCs, with the highest stability among the tested sample cells. Furthermore, the pure MA2Pb3I8(DMSO)2 intermediate phase presents a high long-term stability, which enlarges the operating window for perovskite deposition and thus considerably improves the device processibility.
KW - Intermediate phase
KW - Inverted planar solar cell
KW - Perovskite
KW - Vertically monolithic crystal
UR - http://www.scopus.com/inward/record.url?scp=85013040856&partnerID=8YFLogxK
U2 - 10.1016/j.nanoen.2017.02.019
DO - 10.1016/j.nanoen.2017.02.019
M3 - Article
AN - SCOPUS:85013040856
SN - 2211-2855
VL - 34
SP - 58
EP - 68
JO - Nano Energy
JF - Nano Energy
ER -
