Halide perovskites are promising semiconductor materials for a wide range of applications in optoelectronics. Perovskites have been used to design solar cells, light-emitting diodes, photodetectors, and lasers. However, the instability of perovskite organometallic halide has been described as the biggest challenge to its potential applications for energy harvesting. Recent developments demonstrated the use of graphene for perovskite solar cells as a transparent (and flexible) conductive electrode, a carrier transporting material, and a stabilizer material. The...