Donor–acceptor bulk heterojunction polymer solar cells are
currently showing power convention efficiency of more than 6%.
Thermal annealing, slow drying, additive processing, controllable
self-assembly morphology, adding buffer layer and new device
structure can play an important role in achieving high power
convention efficiency. In order to obtain more than 10% of power
convention efficiency from single layer polymer solar cells, more
investigation must be carried out to explore the fundamental
mechanisms and develop new materials. Development of new
materials is an urgent issue. Many scientists believe there is a best
way to get more absorption and higher open circuit voltage, and a
better charge transfer condition. Toward a controllable interpene-
trating network in the films is also important for optimization of
solar cell performance. In addition, designing novel structures to
gain more absorption and controllable local order of materials are
possible approaches to realize high efficiency and high stability of
polymer solar cells