Perovskite-based transparent pn junction in CuI/SrTiO3 toward enhanced photoelectric response via interfacial homogeneous perovskite LaCoO3 transition layer

A transparent pn junction comprising CuI/LaCoO3 QDs/SrTiO3 was synthesized using the solgel-hydrothermal-freeze drying-sputtering in situ iodization method. The CuI/LaCoO3 QDs/SrTiO3 pn junction achieves transmittance of ∼85%, photoelectric enhancement of ∼2.2 × 103-fold to the intrinsic CuI/SrTiO3, and good stability in 5 months. It can be primarily attributed to the LaCoO3 QDs. In addition to appropriate Fermi level and high QY, the LaCoO3 QDs with carrier inducing–injecting–driving can ameliorate the carrier dynamics for PCE-transparency balance, meanwhile increasing the hole by Cu vacancy. Furthermore, the CuI, LaCoO3, and SrTiO3 can maintain good structural stability for potential photoelectric devices.