Improving
device stability is an imperative area of realizing commercial
utilization for organic solar cells (OSCs). Morphology evolutions
of solution-processable active layers have proved to be responsible
for ubiquitous device degradation due to their profound impacts on
charge generation, transport, and extraction. This Perspective aims
to understand and promote device stability in terms of morphology
control and evolution from the subnanoscale to hundreds of nanometers.
We start with analyzing the role of molecular packing and aggregation
within domains on device stability and then focus on the structure
of phase separation stemming from donor-rich and acceptor-rich domains.
Potential mechanisms of morphology evolution within the individual
length scale and some related reinforcing strategies when suffering
from heating, irradiation, and mechanical stress are discussed. Finally,
we summarize and propose major limitations and future directions for
further promoting research on device stability in OSCs.