Enhancement of photocurrent extraction and electron injection in dual-functional CHNHPbBr perovskite-based optoelectronic devices via interfacial engineering.

Photocurrent extraction and electron injection in CHNHPbBr (MAPbBr) perovskite-based optoelectronic devices are both significantly increased by improving the contact at the PCBM/MAPbBr interface with an extended solvent annealing (ESA) process. Photoluminescence quenching and x-ray diffraction experiments show that the ESA not only improves the contact at the PCBM/MAPbBr interface but also increases the crystallinity of the MAPbBr thin films. The optimized dual-functional PCBM-MAPbBr heterojunction based optoelectronic device has a high power conversion efficiency of 4.08% and a bright visible luminescence of 1509 cd m. In addition, the modulation speed of the MAPbBr based light-emitting diodes is larger than 14 MHz, which indicates that the defect density in the MAPbBr thin film can be effectively reduced by using the ESA process.