High efficiency sequentially vapor grown n-i-p CH₃NH₃PbI₃ perovskite solar cells with undoped P3HT as p-type heterojunction layer

Photovoltaic devices with perovskite materials as light absorbing material were fabricated through sequential vapor deposition of lead iodide and methylammonium iodide with undoped poly3hexylthiophene (P3HT) as a hole transporting layer. The sequential vapor deposition process produced films and devices with the large grains and low defect densities, very small values of dark current, and high open circuit voltages. The thickness of the P3HT layer was a critical parameter for achieving high solar conversion efficiencies of 13.7%. The vapor deposition process also produced devices with a tight distribution of performance characteristics and very high open circuit voltages (0.99 V).