Efficient Singlet Fission in Loose Packing Benzodipyrrolidone Thin Films

Singlet
fission (SF) hold immense potential in efficient solar
energy conversion on account of the vital role in alleviation of thermalization
loss for high-energy photons. Although tremendous effort and progress
have been made, the application of such a potential process in practical
photovoltaic devices remains a formidable task. Therefore, exploitation
of efficient SF molecular systems and in-depth study of their excitonic
dynamics are of great importance to the implementation of photovoltaic
application. Herein, we have developed a series of benzodipyrrolidone
(BDPP) derivatives and delved into the SF dynamics in these loose
packing thin films using time-resolved spectroscopy and morphology
analyses. Results illustrate that efficient triplet formation could
be achieved in all these loose packing thin films with a distinct
crystallographic form and intermolecular packing mode. Suitable excited
state energy levels, strong absorption in the blue–green light
region, and excellent stability render BDPP as a robust SF molecular
system targeted to practical utilization.