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.

单重裂变（SF）在高效太阳能转换中具有巨大潜力，这一潜力源于其在缓解高能光子热化损失方面所扮演的关键角色。尽管在这一领域已投入巨大努力并取得显著进展，但将这一潜在工艺应用于实际光伏器件中仍然是一项艰巨的任务。因此，开发高效的SF分子系统并深入研究其激子动力学对于光伏应用的实现至关重要。本研究中，我们开发了一系列苯并二吡咯酮（BDPP）衍生物，并利用时间分辨光谱学和形貌分析深入探究了这些松散堆积薄膜中的SF动力学。结果表明，所有这些松散堆积薄膜均能实现高效的 triplet 形成且具有独特的晶体结构和分子堆积模式。BDPP分子因其适宜的激发态能级、对蓝绿光区域的强吸收以及卓越的稳定性，成为一种适用于实际应用的高效SF分子系统。