Carbon nanotubes in perovskite-based optoelectronic devices

Halide perovskites have been widely utilized as the light-absorbing layer in a wide range of optoelectronic devices because of their superb optoelectronic properties. However, device performance still needs to be improved before the practical applications of these devices and various specific strategies can be developed. Among these strategies, incorporating carbon nanotubes (CNTs) has been the most general and versatile one. CNTs in the devices could serve as conducting substrates and electrodes, improve charge extraction and transport, act as additives in different components, make devices flexible and stable, and so on. Here, we summarize and discuss recent applications of CNTs in various perovskite-based devices, focusing on solar cells, photodetectors, and light-emitting diodes. First, basic knowledge regarding perovskite devices and CNTs isintroduced, and then the specific roles of CNTs in these devices are summarized and discussed. Finally, current issues are pointed out, accompanied by the corresponding suggested solutions.