posted on 2019-05-23, 00:00authored byDuo Wang, Cuncun Wu, Wei Luo, Xuan Guo, Xin Qi, Yuqing Zhang, Zehao Zhang, Ning Zhu, Bo Qu, Lixin Xiao, Zhijian Chen
The
performance of perovskite solar cells (PSCs) depends on the crystallization
of the perovskite layer. Herein, we demonstrate an effective photoannealing
(PA) process by a halogen lamp. During the PA process, on the one
hand, the lower energy photon, that is, near IR up to ∼1015
nm photon, drives the crystallization of the perovskite film, similar
to the conventional thermal annealing (TA). On the other hand, the
higher energy photon of PA can excite the trapped carriers and release
the space charges, thus leading to an ideal perovskite layer with
better crystallinity and lower density of defect when compared to
that of TA.
A maximum power conversion efficiency (PCE) has been obtained to be
20.41% in the CH3NH3PbI3-based planar
PSCs based on PA because of the increase of Jsc and Voc, much higher than the
control device based on the conventional TA with a maximum PCE of
18.08%. Therefore, this result demonstrates that PA is an effective
method to promote the device performances and reduce the fabrication
cost, which provides a potential approach for the commercial application
of perovskite devices.