PT  - JOURNAL ARTICLE
AU  - Wang, Yanbo
AU  - Wu, Tianhao
AU  - Barbaud, Julien
AU  - Kong, Weiyu
AU  - Cui, Danyu
AU  - Chen, Han
AU  - Yang, Xudong
AU  - Han, Liyuan
TI  - Stabilizing heterostructures of soft perovskite semiconductors
AID  - 10.1126/science.aax8018
DP  - 2019 Aug 16
TA  - Science
PG  - 687--691
VI  - 365
IP  - 6454
4099  - http://science.sciencemag.org/content/365/6454/687.short
4100  - http://science.sciencemag.org/content/365/6454/687.full
SO  - Science2019 Aug 16; 365
AB  - The weak bonding in the crystal lattice of hybrid perovskites used in solar cells promotes surface decomposition and interferes with the formation of stable heterostructures with the charge carrier layers. Y. Wang et al. show that strong bonds are formed between lead and both chlorine and oxygen atoms in a film with a lead-rich surface and a chlorinated graphene oxide layer. This interface was used with common hole-transporting materials to fabricate solar cells that maintained 90% of their initial efficiency of 21% after operation at 60°C for 1000 hours.Science, this issue p. 687Here we report a solution-processing strategy to stabilize the perovskite-based heterostructure. Strong Pb–Cl and Pb–O bonds formed between a [CH(NH2)2]x[CH3NH3]1−xPb1+yI3 film with a Pb-rich surface and a chlorinated graphene oxide layer. The constructed heterostructure can selectively extract photogenerated charge carriers and impede the loss of decomposed components from soft perovskites, thereby reducing damage to the organic charge-transporting semiconductors. Perovskite solar cells with an aperture area of 1.02 square centimeters maintained 90% of their initial efficiency of 21% after operation at the maximum power point under AM1.5G solar light (100 milliwatts per square centimeter) at 60°C for 1000 hours. The stabilized output efficiency of the aged device was further certified by an accredited test center.