Low temperature processed, high-performance and stable NiOx based inverted planar perovskite solar cells via a poly(2-ethyl-2-oxazoline) nanodots cathode electron-extraction layer

• Published in: Materials today energy Vol. 1-2; pp. 1 - 10
• Main Authors: Chen, Wei, Zhang, Gui-ning, Xu, Lei-ming, Gu, Rui, Xu, Zheng-he, Wang, Hai-jiang, He, Zhu-bing
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2016
• Subjects: Cathode electron-extraction layer; Interface engineering; Perovskite solar cells; Planar inverted; Poly(2-ethyl-2-oxazoline); Interface engineering; Planar inverted; Perovskite solar cells; Poly(2-ethyl-2-oxazoline); Cathode electron-extraction layer
• ISSN: 2468-6069; 2468-6069
• DOI: 10.1016/j.mtener.2016.11.001

High conversion efficiency and stability are above all important topics in the current study of perovskite solar cells (PSCs), which determine the future of their commercialization. According to the intrinsic characters of PSCs, interface engineering plays a key role in enhancing both conversion efficiency and stability of PSCs. In this work, we developed a robust interface engineering for “inverted” planar heterojunction PSCs of low temperature and faCELe solution processed PEOz nanodots film. The PEOz nanodots film acts as electron extraction layer and NiOx nanostructured film acts as a hole transport layer in a configuration of ITO/NiOx/Perovskite/PCBM/PEOz/Ag. Such design results in an open circuit voltage (Voc) of 1.07 V, a short-circuit current (Jsc) of 21.93 mA/cm2, and a fill factor (FF) of 77.9%, corresponding to a maximum PCE of 18.28%, in contrast to a conversion efficiency of 11.98% for the same structure devices without PEOz cathode electron-extraction layer. Moreover, the combination of the two layers leads to highly stable planar PSCs and hence high durability. A series of experiments and characterizations were performed and collected to support the discovery. Our results provide a scientific basis for the scale-up production of future PSCs. A low cost, low temperature and facile solution processed PEOz nanodots film as an electron extraction interlayer and NiOx nanostructured film as a hole transport layer were adopted in a planar inverted perovskite solar cells with a configuration of ITO/NiOx/Perovskite/PCBM/PEOz/Ag, resulting in a maximum PCE of 18.28% while the same structure devices without PEOz interfacial layer got a conversion efficiency of only 11.98%. It could be attributed to good band alignment and efficient electrons extraction between PCBM and silver electrode. Both the PEOz and NiOx also contribute to high stability of those perovskite solar cells. [Display omitted] •PEOz was employed as effective CILs for inverted perovskite solar cells.•NiOx NCs was selected to be HTM layer to minimize the Voc losses.•Ohmic contact can be formed at the PCBM/Ag interface by integration of PEOz cathode electron-extraction layers.•Maximum PEC of 18.28% was achieved in our inverted planar perovskite solar cells.•The XPS data directly explored the N elements of PEOz interacting with Ag and I ions diffused in contribute to high stability of those devices.