Electronic coupling between perovskite nanocrystal and fullerene modulates hot carrier capture

The efficient harnessing of hot carriers holds transformative potential for next-generation optoelectronic devices. Halide perovskites, with their remarkably long carrier lifetimes exceeding 10 picoseconds, stand at the forefront of this research frontier. Yet, a fundamental paradox persists: why does efficient hot carrier capture remain elusive despite these extended lifetimes? Here, this conundrum is unraveled by constructing a donor–acceptor model system: perovskite nanocrystal and fullerene hybrids. It is demonstrated that the challenge lies not only in the carrier lifetime itself but in the nature of the coupling between donor and acceptor components. Remarkably, it is discovered that the formation of ground-state complexes, with effective coupling across a wide energy range, not only overcomes the initially forbidden hot carrier capture within these hybrids but also dramatically enhances it, achieving a ≈76% hot carrier capture efficiency. This finding shifts the paradigm of hot carrier capture from extending carrier lifetimes to engineering donor–acceptor coupling, illuminating a path toward practical hot carrier applications.